I always see myself, deluded and incorrect though this may be, as some lovely 20 something.
No matter how I look in the mirror, when I picture myself in my mind's eye I am forever the 20 something young thing that I haven't been for at least 10 years now.
Of course, this self image may yet change.
From what my terrible memory tells me, it did once before at least. The first time I realised i had a faulty mental self image was when I worked in my first school. I was mid 20s yet just couldn't see the pupils as 10 years younger than I was. My brain always told me I was 18. Nothing would convince my brain otherwise.
Now sometime in the intervening 10 years I've changed my mental self image. I may be mid 30s now but my mental self image has refused to keep pace and in that ten or so years has only added 5. In my mind I'm still the youthful side of my mid 20s.
Now I'm actually looking forward to finding out in another 10 years as I start to approach 50, whether my mental self image will have celebrated 30 or not. And if it has, was it's party any good? If it was better than my own 30th I may be a little jealous.
I know it's not just me though. Louise does it as well and so does everyone else I've ever asked about it. There doesn't appear to be any pattern to this phenomena. The mental self image age is different in different people.
I have no real idea why, all I know is I'm 20 something and intend to stay that way.