Sometimes you want to try something you haven't done before. Say, you decide you'd like to try painting. There may be a struggle inside of you about whether or not you can do it. This negative thought could stop you from painting, which might be a hobby or career you would really enjoy.
Take a tip from Vincent Van Gogh.
"If you hear a voice within say 'you cannot paint,' then by all means paint, and that voice will be silenced." --Vincent Van Gogh