[lmm]

That's a contingent fact about the place and era you live in. Medieval peasants - the majority of people who have ever lived - were not dumbasses, not all of them - but there simply wasn't a way for even the smartest to accumulate long-term wealth. At best you could maybe get your neighbours to owe you a few more favours, and maybe once in a generation if you played every card right there might be a chance for a patriarch to acquire one more piece of land, but that's it, that's your lot. (Sure you can work your ass off and produce a bit of extra grain in a given year, but then what? It's going to rot, and selling it for money is surprisingly useless to you)

[ahartmetz]

Money was useful - not as much as today, sure. But traders and tradespeople existed in the middle ages, so you could buy some goods and services. Metal tools and farming implements, harnesses for horses or oxen, pots, clothes / fabrics, maybe woodwork for a house...

Some of these things you could make yourself or were commonly self-made instead of buying, but that, too, requires planning and discipline.

I'm a bit shocked that some people think of medieval life as something like Elbonia in Dilbert comics. Heck, I even find the middle ages a pretty boring time in human history, but I know enough to understand that it wasn't as simple as "everyone lived in the mud and ate mud".

[lmm]

> you could buy some goods and services. Metal tools and farming implements, harnesses for horses or oxen, pots, clothes / fabrics, maybe woodwork for a house

You could buy some temporary luxuries to enjoy, or save yourself a bit of labour on something you'd normally do yourself. But you couldn't really invest in your future the way we would today - everything you depended on had to be something you could make yourself, buying an implement you couldn't maintain would be setting yourself up for trouble. Increasing your productivity with tools wasn't a huge help because you always had enough labor available to hit severely diminishing returns on the land you owned. And any object of value is always at risk of being seized by the local lord or a passing army or what have you.

[ahartmetz]

No disagreement about that. A peasant couldn't even properly own farmland in the feudal system.