The important thing is not just to do these things for yourself when you're single... but to remember to continue doing them after you've found another relationship. In fact, I think it's one of the Most Important Things EVER in maintaining a healthy, balanced, non-self-eradicating relationship... so better start practicing now!
I've gotten married recently, and one of my goals for the coming years (and decades
) is to mark out time for myself, to do the things that I have always loved to do, on a regular basis. You have to stay in tune with who you are, what makes you happy, what makes your "ears perk up," as Jess said.
If you don't, it's not only damaging to your own sense of self, but it will most likely cause your partner to be frustrated at losing the person whom he fell in love with in the first place (unless he's codependent, then you're both in a mess).