John McLaughlin is one of my favorite guitarists. Here is a clip of him being interviewed in 1991. The interviewer asks him about how much he practices referring to another guitarist who claims he does not practice. I think John's answer is great. Here is a little excerpt:
John McLaughlin: “I have this theory. Maybe just because it’s me. If I don't practice it goes down. And just to stay equal, even, I have to work. To improve I have to work harder.”
Interviewer: “I wonder if there is something you have great difficulty with. Everyone in their job has a bit where the little red signals go ‘this is a bit I find difficult’. Do you have bits that ….?”
John McLaughlin: “They’re the worst. But they’re the ones we have to work on the most.”
By the way, here is how great he plays.