Humorectomy

A friend of mine has a theory that the act of getting married causes people to have a humorectomy. He noted how so many of his friends used to be interesting, spontaneous, funny, clever, etc. before they got married. Now they're just bland and never want to go out.

Another friend chimed in with, yes, not only is that true, but it happens, oddly enough, even to people who were living together and essentially married for years before they actually tied the knot. You'd think they wouldn't change, but they do.

Is it because they've "won," so they no longer have to act interesting and keep their beloved liking them?
Is it because they get caught up in nesting and don't care as much about the outside world?
Is it because they're following a standard behavioral mold set by those who have gone before (including, unconsciously, their parents)?

I'm definitely not as interesting as I used to be before I got married. I chalk it up to working too much (no time to read) and having a kid (no opportunity to go out). If I didn't have those things going on, I'd still be sneaking up forbidden spiral staircases in the cathedral at night, and rappelling down cliffs on weekends. I'd be going to Scrabble tournaments and entering strawberry shortcake contests and rehabilitating mourning dove chicks. I feel like the fun, slightly weird, loner-wild Erin is still in there, still inside me, just waiting until I have time in my life to be like that again. I hope she doesn't die. Hang in there, I want to tell her. I'm sorry I'm so dull right now, but I'll be you again as soon as I can!