“If you can do it then why do it?”
“It doesn't matter what you can do if you don't know why you're doing it.”
“If others can do, why can't you?”
“If God gives you something you can do, why in God's name wouldn't you do it?”
“You can never be happy until you understand why you're doing what you're doing.”
“You can give me a thousand reasons why not to do something, but give me one good reason why, and I'll do it.”