The 29-year-old midfielder was happy on Wearside and only accepted a new challenge once an enticing opportunity was put to him.
"If a club wants you and they accept an offer, then that's what happens. That's football.
"I never asked to leave the club. But the club accepted the offer and then I had the choice to come to West Brom.
"It's football and I had the chance to continue playing in the Premier League. It's a good opportunity for me.
"I had three very good years at Sunderland with some great moments. I will always remember the good memories there and the people at the club.”