I hate clutter and I am sure my children hate me for being a Nazi about keeping everything picked up and in its place. We just don't let things pile up. We've only had one house out of 5 with a basement, so that helped! However, I have been married for just about 35 years. We have a lot of stuff, just not clutter. DH has tons of tools, little things for household work. But, they key is, it's all organized in appropriate containers. We have a couple of junk drawers in places, but it would take me like 15 miutes to purge them.
I am not sentimental, either, but I have thrown out a few things that I wished I hadn't, and I knew I would regret it as I was throwing them out. These were more memento types of things, not valuables, or junk. Our next move will be downsized. We seriously will need a storage place, as DH has a whole workshop/bikeshop in our utility room/laundry area. This is what's stopping us from buying a townhouse without a basement. We may end up with a small house. Heck, where would we put our bikes and all the gear that goes with them? We also have a lot of kitchen stuff. That will be gone through, but there's not that much that we don't use.
My current house has lots of cabinets and storage closets, as well as our bike shed (really a garden shed) and a storage loft above the garage. We've cleaned out the storage loft, as it mostly had my older son's junk, and when *he* bought a house, we made him rent a truck and come get it! We also got rid of all of old text books from college. I've moved 5 times, including once across the country, and we are extrememly quick at packing/organizing/unpacking. You can't be like that if you have a lot of junk.