Usually the difference between a guy who Squats 500 and a guy who Squats 200 is a good 3-5 years of solid, consistent graft in the gym.
The longer I train the more I find myself agreeing with Btb's sentiment there. It really is just a matter of time and a consistent willingness to push yourself month after month. Being able to keep that level of enthusiasm and energy toward something which, let's face it, isn't a matter of survival for us. Our lives don't depend on whether we Squat 500, we do it because we love it. It really is a labour of love, why do you think people get so passionate about lifting on these forums. To sustain that love for years upon years requires effort. To pick yourself back up from game ending injuries and then come back even stronger requires mental fortitude. The type of fortitude that makes your goals an inevitability. To have the will to organise your life so that when the time comes that other priorities in life are more important (and trust me, they will be) that you don't completely leave your training goals behind. The younger guys might not understand that one, but trust me you will one day.
Every guy who trains through all that and still puts in the graft after sometimes, decades of lifting is the kind of guy who will reach his goals, who will find a way.