There are many times in my past that I would prefer not to relive but that doesn't mean I want to change them now. College didn't work out but without it I wouldn't have met my wife. Many things didn't go as planned but those things are all now part of what makes me who I am. So a couple small things I would tell myself...
Don't cash out your 401k everytime you move. Find a way to roll it over and keep it saved.
Don't wait for your granddaddy to die to take chances in business. He doesn't leave you enough money to change your life and you waste ten years working your ass off for people that don't care about you.
Stay the fuck away from South Dakota. Things are not what they seem up there and you will leave there broke and beaten down and so does your wife. You would have been better off staying in New Mexico or just moving back home.
You should have taken Spanish. At least in college take Spanish because you will spend a lot of time listening to it and trying to speak it in kitchens.
Don't make a game out of your kids wiping the toothpaste off their faces with your bath towel when they are toddlers. They continue doing it as teens.
That's enough for now. Have fun SG.