I bought my model D used for $250, if I ever sell it I’ll turn a profit :P

I started maxing my Roth Ira out when I was earning $10/hr. Avoid spending money on things that don’t literally matter and save for the things that do. Pay attention to where every single dollar/pound/Euro/shekel goes. Stay out of debt. Keep drug/alcohol use reasonable. Most of the time folks who are concerned about retiring/money have no idea how much they spend on what. Saving for retirement is easy once you start doing it and get used to it, but you need to start early and you need to invest in the stock market. Avoiding chronic illness or accidents or long periods where you aren’t earning income are probably necessary too. Staying out of legal trouble is probably necessary as well.