"I could have stayed put for the remaining two years of my contract and picked up my money without doing a lot," he told Sky Sports.
"Maybe I would have been on the subs' bench and got the occasional game but that is not in my make-up. I am far more ambitious than that.
"There wasn't much contact between me and O'Leary to be honest - we didn't have a great relationship, and didn't speak that often.
"I just sensed he would only play me when he had to, but if the chance came along to get someone else in ahead of me he would.
"I was in the squad, and travelled with the first team but that was as far as it went.
"I didn't have the same relationship with O'Leary that the other Villa players had, and I guessed that if an offer came in he would not hesitate to take it.
"Now I am just glad I can start afresh because I feel the best is still to come."