This is a quote from the song "20 Going on..." by Tsunami Bomb, and it's a phrase I try to live my life by. It was done at Tattoo Zoo in Fort Walton Beach, Florida. The artist freehanded the lettering onto a scratch piece of paper, then transferred it to the skin and started inking. Total process was done in about an hour, and I love it.
In case you can't read it, it says "Be what you're becoming, and not who you were. grab hold of the here and now while you still have the chance."