This is just a test with 20 questions and at the end you are given your mental age. http://mymentalage.com/new I did it twice, the first time I was 8 years older than my age, the second time 11 years older. Whimper.
On that last link I posted above it gave me a virtual age of 33.9 and Ill be 34 soon so pretty good. Can't remember how long it says I'll live but it was early 70's. Don't know how serious one can take that.