i read that you are supposed to keep your fret hand wrist straight. however, when playing on strings such as the E string (the thicker one) and the A string, which are more towards the top of your fretboard (or more towards your head) when you play, it is very uncomfortable and almost impossible for me to keep my wrist straight when playing on these 2 strings. so my question is...is it necessary for the wrist to be straight when playing on every strings? or is it okay if the wrist is bent when playing on strings such as the E (thicker one) and A string? and what is the benefit of keeping your wrist straight?