....oh I did some really simple stuff when I was a kid, but that was always just garage band goof around time. When we gigged it was always rhythm guitar or bass for me... mostly bass. Just never had the chops for lead guitar...

Steve touched on it when he mentioned 'muscle memory'.... which is mostly what rhythm guitar is for me when I play it. Chord changes are easy 'muscle memory' for me. While continuously moving bass notes aren't the same (for me). So when I try to sing while playing bass... the note changing just sorta 'get in the way' of what's going on in my head... not sure why... but when singing & playing guitar..., it all just seems to flow much more smoothly.