P.S. I should add that when I reached 2390 (and won a national chess title), I had an amusing conversation with Grandmaster Nunn (a world-class player and decent chap.)
“Seriously, glee” he said “Nobody rated below 2400 understands chess.”
I was flabbergasted - but after analysing with him (and reading some high-level chess books), I had to agree. 
Yes, I can crush players rated 2000. But there is so much more to learn. Thankfully I never turned professional!