For me it is a question of mind and not age.
As a child I had lots of fun with kids and also with old people. They were fun and made me laugh and let me do things like climbing trees, row a boat, go fishing.
I still enjoy older people, but somehow there are fewer of them - wonder why.
Have also much younger friends with whom I can talk with, laugh with and discuss with.
Had a few not so nice years and have gotten over them. A friend of mine who I see once a year said "You are now just like I remember you were as a yong woman"
A young friend of mine told me "The way you are now is how I imagen you must have been as a young woman"
Even my daughter thinks so.
What age am I?? The birthcertificate age? The way I look - 10-15 years below that birthyear? Or that young person who still is so curious about everything and feel there is so much to learn.