This works in theory, and in practice for some people, but not everyone. For example, I don't have a lot of 'stuff' but I do have a couple of hobbies that require 'stuff' like rock climbing and backpacking. My girlfriend who lives with me is an avid scrapbooker, which inherently means she will have a lot of stuff.

It's easy to not have 'stuff' if your entire life is online, but once you start to accumulate hobbies that aren't online then not having stuff gets much more difficult.

My goal is to not have stuff that doesn't serve a purpose. Nic-nacks, gifts from trips, decorations, etc.

You can put a lot of stuff in a car. I have a fair amount of snowboarding stuff for example, but it does not actually take up all that much space. Camping is probably a better example, you can have an insane amount of camping stuff or a backpack full, but quality dominates quantity.

That's true and I could fit all my camping and climbing stuff in my car, but the picture I get from people who tout "all my stuff fits in my car" philosophy is that they live in a room with no furniture, a coffee mug and their laptop. Having less stuff for the sake of having less stuff doesn't seem to really serve a purposes. Keep what you need and want and ditch the rest. Not that complicated.

That's pretty dismissive of you to assume you know anything about me or my hobbies, actually. A lot of things such as my books and music were converted digitally, but I actually have an entire recording studio setup and my gardening supplies to move as well. If anything I spend a lot of my time avoiding online activities. You can learn to cram a lot into minimalism, not everyone is the hapless nerdotron you seem to think they are.

A good bed? I'm not aware of any that you can pack in a car that won't give you back problems in the long term.

A sleeping bag and a foam roll. Seriously. I did this for years and was fine. Probably just an IME, but I've found that back problems are an issue of being out of shape (low muscle mass) or over usage (bad job, poor ergonomics, etc) and never caused from not sleeping on a bed. If I lift weights or otherwise in shape I can sleep on anything. When I'm out of shape I tend to get back pains from just about anything that isn't perfect.

That's exactly my situation yes. I also never had an issue when I had to share a bed with someone, in fact several people I used to see found it novel. Sometimes I do discard things between moves, selling them off or gifting them and repurchasing them after moves. I could easily do the same with beds if I wanted to.

How old are you? I'm pretty sure that it'll take a toll long term, but maybe that's me.

I'm thirty and I actually began sleeping on a proper Japanese futon mattress specifically because of back issues that were then cleared up. Millions of people sleep on essentially a pad on the floor just fine.

Millions of people also have back problems, anecdote is not evidence :P

I'm only 35, but it could I guess, further down the road. Not sure from a historical standpoint how many older guys that slept on the ground (think cavemen) had back problems, but it could be something (like temperature) that one acclimates to.

What do you do when you have a lady friend over?

I actually had two camping bags and a large roll of foam just for those situations. Usually never had any problems, though I do recall spending more nights at their place than them at mine.

I went to college late (~26 y/o) and by that time I had gotten a bed from somewhere (gift from parents I think). I'm married with a house now and don't live as minimally now, unfortunately.