I started adopting the mindset that set me on the path for FI/RE (Financial Independence/Retire Early) when I was very young. I collected baseball cards when I was a kid and added comic collections when I was a bit older kid.
Early on I was paying attention to the investment potential. I enjoyed not just the collecting but also the idea of making money by buying something and then selling it later for more money (which is the fundamental idea of investing). It came naturally to me.
I never much liked spending money on something that lost its value. For some things, like ice cream, I could happily spend my money even though I would soon have nothing to show for it. But more often I would rather buy something I could enjoy and also believe I would be able to sell later at a higher price.
When I started actually trying to sell baseball cards for money I learned about he difference between reported “value” and the ability to get cash for what you owned. Not only can’t you sell items to a store at the “value” reported in pricing guides you often couldn’t sell them at all (they didn’t want the items at all).
In high school I started renting space to sell at shows. There you were selling to the public (or other dealers). I learned vivid examples of the challenges of turning assets into cash. And I also learned about the weaknesses in the economic ideals such as the market being efficient. I saw how often the very same product (the same baseball card) for sale in the same hall would have very different prices (over 100% more was not uncommon) and the sales were often not close to the best buys. The friction in this situation was much smaller than the typical purchase (all the items were in the same room, just a little bit of walking created the friction).