I figure I'm about 20 years older, at least, than the target demographic for The Sisterhood of the Traveling Pants 2. I understand that there are some movies where I'll always feel a little old or out of touch, because they're just not made with me in mind, no matter how good or bad those movies are. Fortunately, I had no trouble empathizing with the four young women who are bound to friendship through their magical bifurcated nether garment -- more so than I did with the Sex and the City gang, who are much closer to my age.
Like Sex and the City, Sisterhood of the Traveling Pants 2 works better if you know the characters already through their previous appearances, because you're already emotionally invested in them. I hadn't read the young-adult novels by Ann Brashares, but my sister, who is a big fan, filled me in and we determined that this movie is based mostly on the fourth book in the series, with a few changes, so even if you've read the books you get some surprises.