"I think a lot's changed in 16 years," he told MUTV. "But I'm enjoying more football more than ever. The nearer you get to the end, you try and enjoy it as much as you can. At 18 or 19, you think it's going to go on forever and obviously it doesn't.
"I'm enjoying it, we've got a great team at the moment. Obviously winning the Premier League last year was a great buzz for everyone and hopefully we can do it again.
"I feel as fit as ever and I'm enjoying it as much as ever as I've just said so hopefully I can go on a bit longer."