I can’t do that.
I can’t eat like that.
I can’t behave like that.
I can’t listen to that.
Is it really that you can’t or is it that you don’t want to or choose not to? Saying that you can’t do something is a reflection of your thoughts regarding your ability. Changing your language and replacing I can’t with I choose not to or don’t want to will signal to your mind that you are in control.
I will warn you that there is going to be a social consequence to you if you decide to tell people that you don’t want or choose not do something. So be careful how you wield the power of your own choices and vocabulary around the people you spend your time with.