There's a lot of different ways that a song would be a challenge to parody. There are a lot of songs that would ostensibly be a good candidate for parody, yet I can't think of a clever enough idea. Some songs are too repetitive for me to be able to fashion a humorous set of lyrics around. Some songs flat-out just don't work creatively for me.
I suppose I had my rock star fantasies while I was singing into my hairbrush in the bathroom mirror, but I never really consciously said, 'OK, this is what I'm going to do for a living and I'm going to be Weird Al.'
Somebody will come up to me after a show and have me sign their arm, and the next time I see them my autograph has been permanently inscribed on their arm.
In a genre where most of the artists are one-hit wonders, I've been able to hang around longer than most "serious" acts. I pride myself in being a very talented leech.