True Selflessness..?

Here is an interesting thought...

One of my resolutions is to volunteer.  My life hasn't exactly been a walk in the park, but it could definitely have been worse.  I'm alive and well and think that I am all the better for my tough spots.  So I wanted to do something to help others who were less fortunate than myself.  What better way to do so than to volunteer?

Here is the thought, though.. Ultimately, I am volunteering to make myself feel better.  I want to volunteer to feel good that I am helping someone.  If I wasn't going to get that good feeling, I wouldn't be donating my time and effort.  So is it truly being a good person? Or is it just a different form of being self-centered?