As a theater critic who travels a few times a year, I often catch Broadway musicals before they start touring and occasionally I get to London, where there's always a steady stream of work headed to Anglophile New York. What I've discovered through repeat visits may surprise you: I don't always agree with myself. This is not the kind of confession that the more thin-skinned members of my profession are likely to make. But it's not that I'm any more courageous about admitting mistakes or regrets of opinion. It's just that I recognize that my perceptions, like everyone else's, are altered by personal history. Not only does my own peculiar life story influence my response, provoking tears or impatience or a burst of mischievous laughter depending on the conscious and unconscious connections that may arise (confirmation alone of Oscar Wilde's notion of criticism being the highest form of autobiography). But my theatergoing past comes into play as well. Musicals tend to tour with more fanfare than straight dramas while not being as dependent on marquee casting, so let me confine myself to those shows. Let's start with the freshest example before us: 'Spamalot.' The New York production may have been the best of the three I've attended, but the first time I encountered the work, I think I may have expected something socko from this mega-hit directed by Mike Nichols. For the Vegas opening, my sights were lowered not just because I was already acquainted with the silly high jinks but also because I knew that this was going to be a truncated version, designed to get spectators back to the gaming tables without the delay of an intermission. Interestingly, though the Vegas version had more flaws, my laughter was less burdened by the musical's pedigree. I approached the production at the Ahmanson with an informed yet open mind -- and giggled almost the entire way through the show. The third time may have been the charm, but more likely I was better poised to meet the show on its own terms. Expectations, it can safely be said, guide as often as they mislead -- a truth borne out by anyone who has ordered a favorite dish at a restaurant only to find its flavors disappointingly obvious, though the chef assures us he has prepared it with no more salt or garlic than usual. Human beings are naturally fickle when it comes to matters of taste. (How many of you are living right now with a completely wrong couch?) Only an ideologue -- or a bore -- insists that his love of something is fixed. My spine tends to stiffen when I'm supposed to go crazy about something, either because of other people's gush or my own. As a result, I'm often one of the last holdouts for movie blockbusters. I saw 'E.T. the Extra-Terrestrial' only this decade and have yet to see 'Forrest Gump.' It's not that I have anything against crowd-pleasers. I just hate being bullied into any cult, mass or minor. Maybe this explains the divergent reactions I had to 'Wicked,' one of the most commercially successful musicals of the new millennium. I saw the show in New York after it had opened to mixed reviews, but when it was already clear that it was going to be an unstoppable juggernaut at the box office. Although I adored the leads, Kristin Chenoweth and Idina Menzel, I found the production to be every bit as bloated as the more discerning critics claimed it was. Needless to say, when the long-running Los Angeles production of 'Wicked' opened in February 2007, which followed the Broadway touring version in 2005, I didn't have especially high hopes. But a funny thing happened on the way to the Pantages: Not expecting to be blown away, I uncovered an enormous amount of musical theater pleasure that had previously escaped my notice. No, the stagings weren't identical, but it wasn't the new cast or directorial renovations that changed my mind -- it was the familiarity with a show's shortcomings that allowed me to better see (and enjoy) what lurked beyond them. Touring shows get makeovers all the time, but the core of a new musical isn't usually radically improved or marred. Changes in vantage and perspective are more potent, in my experience, than the rejiggering of a big number or the nixing of a special effect. More to the point, we can't help gauging work by the ideal conjured by our mind's eye. An instructive case in the way the shock of the imperfect new can disproportionately affect one's overall appraisal is my flip-flop over 'The Light in the Piazza.' When I first saw the work at Lincoln Center's Vivian Beaumont Theatre in 2005, I was unable to go along with a crucial plot point. Clara Johnson, the young ingenue traveling with her mother in Italy, is supposed to be mentally impaired after being kicked in the head by a pony when she was girl. For me, the character, who's able to attract a dreamy male suitor and master fluent Italian (unlike her mother), wasn't so much ambiguous as totally farfetched. But to my astonishment when the show opened in Los Angeles in 2006, I found myself not just completely seduced by Adam Guettel's sumptuous operatic score but also impressed at the finesse with which Craig Lucas handles the exceedingly difficult challenge of adapting Elizabeth Spencer's tricky novel. How did I manage that turnaround? The only explanation I can come up with is that, prepared for an irksome flaw, I was better able to limit my annoyance to it and thereby more able to appreciate the majestic colors that otherwise had been eclipsed for me. Of course, the reverse has proved just as true. When I reviewed 'Billy Elliot: The Musical' in London in 2005 for the Village Voice, I described the work as 'remarkably satisfying' despite the 'mere adequacy' of the show's parts. But figuring my critical ledger would once again come out on the positive side when I reviewed the Broadway version last fall for the Los Angeles Times, I was bitterly disappointed in a production that kept rubbing my nose in all that mere adequacy I was miraculously able to overlook the first time around. Sure, the New York production was a few notches inferior, but would I have been similarly swept up in the working-class boy's ballet dreams had I gone in cold? Now the point of all this isn't to debunk the validity or usefulness of criticism. A review, unlike a consumer report, is more than just a positive or negative verdict. The goal is always to provide an enriching discussion, so that readers can ultimately make up their own irrepressibly opinionated minds. But the moral of my tale is that critical favor (or disfavor) isn't eternal. In an essay on Charlotte Bronte, Virginia Woolf shines some insightful light on the evolving nature of our response to art: 'To write down one's impression of `Hamlet' as one reads it year after year,' she writes, 'would be virtually to record one's own autobiography, for as we know more of life, so Shakespeare comments on what we know.' 'Billy Elliot: The Musical' is unlikely to ever serve as a reflecting mirror for our deepest selves. Yet what will I think of the show when it eventually finds it way to Los Angeles? I can hardly wait to find out. McNulty is a Los Angeles Times theater critic. 