How old would you be if you didn’t know how old you are? And why?

Regardless of your actual age, what do you think of yourself getting older? Are you 40 years old, or 40 years young?

Personally, I would be about 45 years old, because ageing makes no difference to me. I feel very young, I live an excellent healthy lifestyle, and have few complaints about my life apart from my diabetes. I would be much younger, but wouldn't wish to be in my 20s. That would be too little knowledge and too much angst!!

So if you knew nothing about your birthdate, how old would you be today, and why?