I lift to get stronger. I'm not a powerlifter; I don't care about how much weight is on the bar, except as a measure of how much I'm improving. I want to get real-life stronger. Moving couches, carrying suitcases, helping friends, intimidating potential muggers.
I lift to look better. Let's face it, everybody who works out wants to look better, even if that's not their primary motivation. I like the fact that people think of me as in shape, physically capable and, in some cases, attractive.
I lift to be healthy. Healthiness has been important to me for a long time. My Dad had a heart attack when I was young, and ever since, my family has eaten healthy. My Mom takes walks every afternoon before dinner, and my Dad gets up and goes to the gym before work. That's one of the many great things my parents have done for me -- show me by example how to live a healthy life.
I lift because it's something I can control. It doesn't matter what else is going on in my life. My best friend could be dead, my girlfriend could be a promiscuous cokehead, my business partner could be a clinically depressed double amputee and my mother could be dying of cancer, (I'm watching Forrest Gump, can you tell?) but none of that matters in the gym. All that matters is I show up and I work as hard as I can. If I do that, I'll succeed. I'll get stronger, I'll look better and I'll be healthier. That's a kind of control I don't have in the "real" world.
I lift because it's fun. Maybe I'm weird, but I get a kick out of moving heavy stuff around in the gym. It's like a little competition against myself. If you're playing Nintendo, you try to beat the next level. When I'm playing in the gym, I try to master the next amount of weight on the bar.
But mainly, I lift because if I don't, I'll have nothing to do after work but sit on my butt and watch TV.