It reminds me a lot of Forrest Gump in that we've got a a goofy character who is edited into a ton of 20th-century historical landmarks; he is completely apolitical, loves to blow shit up, and is delightfully devil-may care. His elderly self hasn't changed in the slightest, and so we can continue to see the world through a pair of skewed eyes that are nonetheless quite fun. At first, I thought this might have turned into a modern-day Candide, but the story is still focuses very much on story and has veered away fairly successfully from allegory. 
 So, after finishing the novel, I can say that it has successfully veered away from any type of overt allegory, may the allegorical heavens be praised. On the other hand, I enjoyed the way that our intrepid hero managed to comment about so many political features of the 20th century by being so apolitical. I personally enjoyed the progress, having read and enjoyed so much history in much the same way the author has. He stayed away from some hot topics of debate and blithely character-dropped the big movers and shakers and it was a blast. I understand there will be a movie? In that case, I certainly hope the cast of actors are up to the job or the CGI gives more than credible performances or else the movie will bomb very hard, otherwise. The novel's strength lies in the reader's nodding at events they've either lived or have a more than passing interest in. Otherwise, the novel becomes a novelette about the zany adventures of craftily created random characters that are so much larger than life precisely because they also have to stand up to real people in the past that did so many great things. (As we are made to believe for our intrepid hero.) If that's the case, then it's a decent enough comedy, but if you're taking the whole novel as a piece, then I'm sure you will be pleasantly surprised by the stroll.