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’d highly recommend playing Dance Dance Revolution, if you’re at all interested. Very fun way to burn lots of calories. There’s an open source clone called StepMania. If you really end up enjoying it, you’re going to want to invest in some high quality metal dance pads. Worth every penny though, in my opinion.
By the way, I’m 400 pounds. I know your struggle. I’ve lost well over 100 pounds playing StepMania before. Unfortunately I’ve had some bad events put me in a bad depression, which caused me to gain it back.