In being taught, and in reading many tutorials and posts here, It is recommended that the thumb on the left hand be positioned behind the middle finger or whereabouts. But every time I see a bassist on tv (not many times though, even the back-up singers get more camera time ) his thumb is practically hanging over the neck. Is there a reason for this? Is this similar to when they teach you driving with hands at 10 and 2, but as soon as you get your license your gangsta-leaning with only one hand on the wheel cause it feels more comfortable? Or is it that we are mostly seeing pop bands and not fully experienced bassists? Also, I play with curved fingers, and 'they' all seem to have flat fingers. Any ideas?