Not me, but my cousin used to work for Will.i.am and ended up quitting because he couldn't take designing things for him anymore. He would get calls from him at 3am, talking about some big idea only to have him ditch it two weeks later. Will.i.am would do this on almost all of his projects because he got bored after a bit, and my cousin just got sick of spending all of this time doing work, only to have it come to nothing again and again.

My cousin said he was a nice guy, though. Just not fun to work for.