You can do anything you think you can. This knowledge is literally the gift of the gods for through it you can solve every human problem. It should make of you an incurable optimist. It is the open door.
You can't do anything to be funny. That's cringeworthy. If your humor comes out of a place of love every time you don't make the joke bigger than you. The funniest comedians are in touch with their emotional level.
