Yeah, I feel you there. I usually have a 30 minute threshold for drawing. Anything more than that & I have to evolve it into something like a painting. There are a few exceptions, but patience is not my strongest point.
Thats strait bro I never really know how long it takes me to do a piece I just enjoy drawin regardless how long it really takes. I get whatchu mean on patience I have a hard time with it sometimes too, but a drawin usually turns out lookin good when u take your time with it.