^This^
The large majoritty of people who play pool don't have a prayer of being a AA or world beater. They simply do not have the natural talent and genetics to reach that level. People's brains are all wired differently, some people excel at math, some are phenomenal writers, some become the next Syndey Crosby or Wayne Gretzky, 10,000 other amature hockey players who were just as into the game at age 6 simply did not show the same level of talent and rapid increase in skill level and fell behind.
Pool is not different, most people are simply not capable of making it to the pros. I know tons of players who have put in crazy amounts of practive, more then alot of players WAY better then they are, but they hit a ceiling that is in general their peak potential level and they don't get much better despite still putting in massive amounts of practice and constant competitive play. Players with higher potential don't stop at that level, they simply keep improving and they peak at a much higher level.
I know I could have been "good" at this game if I had commited massive amounts of time into it. I know how good I can get pretty quickly if I start playing 20-30 hours a week and start competing in tournaments and gambling. But I know for a fact that I do not have the capability to be Alex Pagulayan level in the game, it does not matter if I put 60 hours a week in, travel the world playing in constant tournaments and gambling, commit my life to the game. I would get good, I would be in the mix of the short stop level of North America, but compared to SVB, Alex, Wu, Hohmann, Souquet? Not a freaking prayer, I never had a chance at that level. It is simply not in me.
It does not matter nearly as much if you are 40, what matters is how much potential natural talent you have in the game of pool. The age thing is about 2% of the equation, 90%+ of the equation is how much natural talent you have and what your peak level of play that you have in you is. If it is below AA/World Beater level then you don't have a chance now and you honestly never did. And that is the reality for 99.99% of the players in this game. Sorry, but that is the way the world works in ALL of the things we might undertake. We don't all get to be the next Sir Issac Newton or Albert Einstein either, it does not matter how much you study, 1000's of people in physics worked just as hard as they did, but they were simply not born with the natural ability and mind that made Newton and Einstein do what they did.