Considering safe-cracking as a profession? This might be just where you should start. Build your own safe with a personal lock combination, store your most precious items in the safe (jewelry or candy, your choice), and then promptly forget your combination! Follow the handy steps in the instructions to master the mix of slow knob twists and careful listening to tumbler movements that will open the lock.
Will you retrieve your items, or will you have to hire a locksmith? Try it and see.