What does it mean?

I am on the cusp of becoming fifty years old, and I have no inkling of what this means.
I look like the men that I have always called "Sir".
Yet, in my own head, I am as I was in my twenties and thirties. Fact is, I have no idea where the last twenty years have gone. This is no paean of regret, but rather a Bemusement.

I love toys, and the kids shows of my youth. I am a devotee of the animation arts. Fact is, I find them to be the most creative and original motion picture story forms extant. I get on well with The Younger Set, and try desperately hard NOT to be the Dutch uncle.

Bottom line, I don't know "how to be fifty", so I guess I'll just carry on as usual.

Maybe I'll get it when I'm seventy.