Just about the only advantage of being old is that one can look back on one's achievements if any and reminisce on what one could have done or even should have done. Naturally everyone's circumstances are different but how would you plan out your future if you were 21 again ?
Not get married or kill my (then) wife. Buy and hold a basket of tech and internet stocks with wide training stops. Approach every decent looking woman that so much as made eye contact with me.
Perhaps need to look at it 2 ways... and with different response. 1. If you could go back to the time when you were 21 with what you know now. 2. You could become 21 NOW and have the common sense to accept Grandpa's Wisdom. (When I was 21, I was eagerly looking forward to the future and all of the good things it was supposed to hold for me. NOW... I'm just hoping to get to live out my life before the government jack-booted thugs come haul me out into the street and put a bullet behind my ear just because they want to take my house.) This is no longer my Grandpa's America. :>(
Buy MNST in 2003, cash some out in 2009 and use the money to back a small startup called WhatsApp. Oh, and bang all the girls that Lucrum approached....the day before they made eye contact with him.
I would buy a combi van and go around the other countries in Europe. Playing music, hunting for antiques and of course a bit of trading. Might even have a bit of a look for the Reichsbank gold in Bavaria or the amber room in .............
Where did your ancestors come from ? Your nick sounds Greek. Maybe you should call in on your cousins in Europe ? They could be rolling in the money.