Figure out this rebus.
Boy : Can I dig a hole?
Dad : Well sure, why not?
Boy : Can I climb a tree?
Dad : Yes, sir!
Boy : Can I jump off the roof?
Dad : Of course!
Boy : Can I fly in the sky?
Dad : Yes, son, you can!
Boy : Can I go into space?!
Dad : Erm. No, I'm sorry, son. You can't do that.