Because Superman did it. Seriously, I have read that several later artists did that because it was done with Superman and it was done with Superman to break up the blue.
My first thought was that was not the work of a professional. So why did he hunt down Don? Just to share a drink with him? Or did he just happen to run into him at the bar?
But they live in their van until they succeed and you have no van. (At least that is the story I have a few times including from Jim Carrey who also dropped out of school)
Because Superman did it. Seriously, I have read that several later artists did that because it was done with Superman and it was done with Superman to break up the blue.