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 cannot hold on to anything good. You must be continually giving -- and getting. You cannot hold on to your seed. You must sow it -- and reap anew. You cannot hold on to riches. You must use them and get other riches in return.