I cant practice the chromatic scale for hours let alone one note...that sounds like obsessive compulsive disorder if I'm not mistaken.

Anyway..Tweak
I was at a point where I thought I could play ANYTHING put in front of me.Well,I was learning "Domination" from Pantera and the beginning of the solo was cake...but then I tried learning/playing the first ascending run and quikly found out that I was nothing.I still cheese my way through that first fast ascending run.Just last week I was watching John Petrucci(some instruction video)and realized I was nothing again!
You get the point.

Later! \m/