Hair trends go through cycles. The styles seem to go around and around through history, and once something enters the zeitgeist for a third time, it's safe to say it's timeless — and this decade the shag haircut is getting that distinction. In the '70s Goldie Hawn was the shag queen. Then in the '90s Meg Ryan put her own twist on the layered look with bangs. This year the shag is making a huge comeback, j ust take Julianne Hough as an example.