Of course you can. You can make a promise to yourself, right?

A promise ring will help you with that promise as a perfect reminder every time you look at it. Also, people may ask you about the ring. Then you can tell all about the reason (if you like) and the story behind it.

And the more people know about the promise you made to yourself, the more you want to keep that promise. So not only can you buy yourself that gorgeous ring, it will even help you to keep that promise.