If you could travel back in time 20 years?

You know, they say hindsight is 20/20, but I disagree.  Sometimes we don;t see the past as accurately as we should.  We tend to remember only what our pea-sized little brains want to remember, or those things that were too traumatic to forget.  Either way, I would bet we don;t remember the past exactly as it is was.  I know I don't.   I don;t know if I would give myself any tips even if I could remember what to tell myself about.  That said, I am sure there are several things I should change, several things I could avoid.  Since the advice is for myself, there is no telling the other guy not to get hit by that car, or trying to stop the Sept 11 attacks, or anything like that.  Only advice for myself.  Problem is, I don;t know how changing something in the past would ultimately change where I am in the present.  I really kinda like where I am in the present.  I have a wife , 4 great daughters, and 9 grandkids, plenty to be happy about and thankful for.  Sure, if I think about it, I could tell myself to pay off the house early and not refinance, or "don't buy that car, it is a lemon," and stuff like that...but to change that may change what I have today, and I don't know if I would risk it.  OK, maybe I would...one little thing.....Buy Microsoft or Google stock early....yeah that's it.  Then buy all the kids a house with the money......but then what if that caused them all to move away to big houses, and not see ol' Dad as often?  What if the kids turned out differently because the financial situation was different while they grew up?  I guess I don;t want to risk it after all.  No advise for the younger me. Nope.  (well...maybe if I save the money and don;t let anyone know I have it......)