I use Ubuntu on a daily basis, but I've tried Gentoo, Linux from Scratch and FreeBSD on VirtualBox. In those, I was looking for the experience of building all

I use Ubuntu on a daily basis, but I've tried Gentoo, Linux from Scratch and FreeBSD on VirtualBox. In those, I was looking for the experience of building all these layers of software, one on top of the other, like a set of dominoes falling backwards in time. After a few hours, you get a giant, baroque, colorful picture of software tools which built itself, and it's for you to use. I can't think of any other professional discipline which allows you to do so.