I think there's a tipping point in any skill where you've learned enough or advanced enough that practicing becomes fun instead of a chore.
I think I'm at that point with pushups.
My standard pushup limit used to be about 20 before I'd start hurting and give up. At a family reunion two (?) years back, we had a pushup contest, and I think I got all the way to 30 or 35 before collapsing. A few days ago, however, I did 65 pushups in a row. My practicing is paying off, and now it's fun to see how many pushups I can do.
The past couple days I've been doing 250 pushups in the morning. Not all at once, I do a set of 10, 20, 30, 40, 50, 40, 30, 20, and 10. It's a great feeling, feeling like I'm actually in some semblance of shape.