I think if you talk to the experts in any field where you have to take on a unknown challenge, where you're going to be working on it for a long time you'd find that to work themselves up to their best performance and really throw themselves into it, you know, spend all these hours in there and ah, give it their. . . give it their best that optimism plays a role.
Have your fun, my dear; but if you must earn your bread, try to make it sweet with cheerfulness, not bitter with the daily regret that it isn't cake.