What's in a Name?

I started a new writing project, and all was going well.

Or so I thought.

When it came time to name the antagonist, a great name came to me. A day or so later, I remembered that I had given a character that same moniker in a story from high school.

I have searched high and low for a new name, but nothing fits as well as this name.

And then I realized, these are two totally separate characters, and just like there are two totally different people in the world who share a name, it's just that: a name.

However, I was wondering...how do you name characters? And, have you ever used a name more than once?