I think I'm simply lazy.
But I've been able to cultivate caring about particular goals/activities/habits, and then, with respect to those, I'm not so lazy - because I found them to offer frequent or large enough rewards, and I don't feel like I'm missing out on any particular type of reward. If you think you're missing something and you're not going after it, that might make you feel lazy about other things, even while you're avoiding tackling the thing that you're missing head on.
This doesn't answer your question. If I was able to do that, then I'm not just lazy.
r/Fitness does a weekly "Moronic Monday", a judgment-free thread where people can ask questions that they would ordinarily feel embarrassed for not knowing the answer to. I thought this seemed like a useful thing to have here - after all, the concepts discussed on LessWrong are probably at least a little harder to grasp than those of weightlifting. Plus, I have a few stupid questions of my own, so it doesn't seem unreasonable that other people might as well.