The limits on your own mind are different than the limits in the real world. However the limits on your mind prevent you from doing stuff that is actually possible, making them impossible by default.
The real answer for everything is: I dont know.
If you think you know, you´re in trouble.
If you think you know, and what you know is that you “can’t”, you just materialized that.
Say, if you go to the gym for six months, do the proper diet, do salsa and acting classes, break your comfort zone, host parties and make new friends, go spend time overseas – and by the end of it you didnt experience any transformation, then you “know”, or you almost know.
Knowing that you cant without trying is just a defense to protect your current comfort zone.
So it´s not really a “cant”, but a want. You dont want. That´s ok. But it´s not about what´s possible, but about what you´re willing to give up in exchange.
Talking you out of it wont work. Even forcing you do to the actions wont work since you would sabotage the process.
But if life forced you, by burning your house, burning your country, burning your life, and you had to survive by changing – you would do it.
The excuses are a waste of time.
You want to dance? you can. You want to become more extroverted? you can. You want to play tennis? you can.
Can you be as good as Federer, as charismatic as Clooney, as successful as Bill Gates? you´ll find the limits there. Because you´re comparing against other people, you´re entering a competition.
You can do a lot of stuff. It doesnt mean you will “win” nor that you´ll be “as good as”
Though, chances are you´re using the “as good as” as the excuse for not doing. The two are unrelated. Say, you dont need to be “as good as” the french masterchef in order to have a restaurant. Dont need to be Clooney to have charisma. Dont need to be Federer to play tennis and win tennis matches. No one of these guys are preventing you to learn and have your own quota of success.
The not doing is.