You'd be surprised if you put your mind to it!! You never know, and as cheesy as it sounds, if you start off thinking you can't do it, you won't be able to do it, but if you at least have one part of your brain that says "hey, maybe I can do it" then that's a start!!
You have to like, allow your mind to think positive, it's so easy to say you can't, saying you can is harder because most of the time people are afraid they'll let themselves down, but just know somewhere you do have what it takes, whether you use it and find that strength is completely up to you