In fairness I’ve been a Mac user since 2007, but even with my occasional flirtations with Windows, I’ve not used anything higher than 10.

My wife’s machine is running 10. I heard her trying to install 11 via a VM the other day to see how she got on with it, and I don’t think I’ve ever heard anyone swear at a computer quite so much in quite so short a period of time.

Her machine is still running 10.