If you have children or grandchildren, listen to how often they may say, "I can't." Then listen to all the adults around you and how often they too may say, "I can't." Many times when adults are saying, "I can't" they really mean "I won't." How often are we ourselves guilty of doing that? When we receive an invitation for something we don't really want to do, we say, "I'm sorry but I can't................." When we have an argument with our spouse or significant other about something which needs to change (and which we do not want to change) we say, "I can't..................." When we need to exercise or lose weight, how many times do we say, "I can't............" when in reality we really won't do what is necessary to discipline ourselves to do it. On the other hand, if your boss gives you an assignment deadline I doubt you say, "I can't............."
In truth, there are many things we do not want to do, but there are few things which we can't do. So if you hear yourself saying, "I can't.........." too often, then it is time to