Doesn’t have to be a thing you bought. Just some thing you didn’t have but then once you did it expanded your scope of actions.
The first obvious example that comes to mind is a car. Plenty of drawbacks to prevalence of cars, but being able to go where I want when I want, and far away, is very transformative.
I’m interested in other examples of things that aren’t just useful, but that open new possibilities.
I moved to a different country driven by a wanting to become worldly rather than for economic reasons.
Facing a whole new place, with a different language, different social norms and expectations and even different living conditions, like that on your own makes you massivelly more adaptable to new environments, as a later move to a different country showed as well as living for a couple of months in yet another one.