Basically just things you were convinced you needed/wanted and then realized you didn’t.
Like a great example for me is when I was house hunting about 2 years ago, I was really looking at kitchens and the idea of the “great kitchen for entertaining.” I did not have the budget for this kind of house. Like I could get a loan for a house which had this feature, but I didn’t want to extend that much debt and have that high of a mortgage. Because debt terrifies me.
And dumbass me took waaaaay too long to realize I didn’t need a larger kitchen with an island and all the entertaining space because I rarely entertain anymore*. Back in my late 20s? Yeah I had people over fairly often. Then they started having kids and my social life changed drastically because my friends had kids!
Anyhoo, the house I ended up buying does not have a big kitchen and a dining room and the big island etc etc. And my small kitchen is still lovely and nice and works great for me.
*Seriously aside from my parents, I’ve had people over twice in the last 18 months. So glad I didn’t spend an extra 25-50k for space for people who don’t live here and never visit.