I often think that as long as people smile and laugh, they look like happy children. Someone could be 120 years old, if he/she is smiling happily, I see a kid. :)
And I started listening to positive affirmations almost 3 years ago. One that I like a lot is: I am healthier, happier and younger with every new day. I don't know how long I can hold it up, but for now, it worked out. I am looking younger today than back then.
Perception follows expectation.
I love that!