Literally (sorry about the pun).
Thank you all for responding to my circuit-diagram problem. The wonders of the internet and the kindness of strangers will never cease to amaze me. Thank you, Paulbo, Shawn and Nikki!
The answer is a SPDT (single pole, double throw) switch. The place to buy it is Radio Shack. No need for banana peels or nutella or foil or anything. Here is a link to a very illuminating (couldn't resist another bad pun) circuit diagram Paulbo sent me.
And here's something even more bizarre than my unworking circuit diagram. Yes, apparently I made this same thing but with three bulbs last year (and used paper clips and paper fasteners for a three-way switch). And forgot. Apparently in throwing out one bulb from the mix, my brain went out the window as well. I have always suspected that my short-term memory was very lacking, but I hadn't realized till now how lacking.
Also, why didn't I ask my husband? Didn't he graduate with an electronics degree? Didn't he redo the funky electrical wiring in our house last year with my (now our) multimeter? Wouldn't it have been such a romantic note to leave on the kitchen table for the morning, "Hi dear, here's a circuit diagram that is driving me nuts. Wanna solve it for me?" Ahhhhh. The misery of hindsight.
Anyway, I will sleep tonight, thanks to you guys and gals. Thank you!