Between ages 18 and 25, I changed career aspirations more often than I changed my underwear. And even after I kind of defined what was the lifestyle I was after, it wasn’t until I was 29 that I clearly defined what I wanted for my life.

I want numbers!!! :)

More seriously, I agree with you that it is very important to be able to define a purpose if ourselves in life. What do we want to be remembered for! But this purpose should not be frozen. It can (should?) evolve according to experience. My own purpose has already changed several times during the last 10 years.