Sunday's game was the 29-year-old's first since recovering from a knee injury that kept him on the sidelines for seven weeks.
"It feels great," Bundesliga.com quotes him as saying. "It's always nice to score three goals in a game - it's not something you do every week and I haven't done it at all this season. My last hat-trick was ages ago.
"I think it was my best game so far this year. I was really up for the game and, after working so hard on my comeback, so to play again - and score - made it all worthwhile.
"I didn't play on my own. We've got plenty of good players in our ranks but you need to have the commitment and the right mentality throughout the entire season to succeed."
Schalke are currently fourth in the Bundesliga with 49 points from 31 matches.