Screaming...
About this time last year I got a Mac and have been absolutely loving it.
I cut my teeth on Unix back in the 70s and to me, Apple got it completely right.
This morning I logged onto a Windows machine I hadn't touched in nearly a year.

While I use Windows to do development at work, I'm usually in Eclipse - well-insulated from the OS.
However, this brief taste of what I left behind, actually getting into Windows itself and having to use it...
Clearly, a century ago Edvard Munch had anticipated the feeling of a Mac user having to occasionally return to a PC.