How do you feel about single-arm kettlebell overhead squats? Or pistols? How about muscle-ups or handstand pushups? How many of these things are you planning to scale or modify for the rest of your life?
All of you have come into the gym at one time or another and did something you never thought you could. Or more accurately, something you never thought about at all. Now, however, you have a whole new set of experiences and beliefs about what you can and can’t do. And all of them are crap.
A belief system is based completely on thoughts. If you think you can’t do it, a belief is established and then your actions turn that belief into reality. It’s the whole “argue for your limitations, and sure enough, they’re yours,” thing.
It’s very simple. If you think you can’t do it and believe you can’t do it, then you will never be able do it. If you think you can and believe you can, then more than one possibility exists for you.
P.S. This applies to more than CrossFit.