Cahill still speaks to some of the Villa players and admitted it was great to see some of the youngsters getting their chance to shine for the first team.
"It's nice to see the likes of (Marc) Albrighton and (Ciaran) Clark playing because they were just youngsters when I was there," he told the Birmingham Mail.
"To see them coming through is credit to the club.
"When I was there the fans were great and when I left there was no ill-feeling towards the fans. They were great to me. It wasn't the fans who chose to get rid of me.
"When you get a little knock back in your career, it gives you something to strive for.
"In the back of your mind you're always thinking 'I'll show you'.
"I know now that me leaving was the best thing. Martin O'Neill let me go and he obviously felt that was the right thing at the time.
"But you go on and want to prove people wrong. That's what keeps you going."