Installing beta operating systems on your gadgets can be exciting, but installing them on your Apple Watch comes with a few caveats.

It’s certainly tempting. Betas give you early access to all the cool new features and maybe even let you try things that never make it into the final release. But a beta is a beta for a reason. It’s unfinished, unstable, and still partially untested.

You often hear the patronizing advice that you shouldn’t install beta software unless “you know what you’re doing,” but what exactly does that mean? And why specifically should you avoid the beta on the Apple Watch?

Last year, for example, Apple’s iOS 13 betas were notoriously unreliable. They added many new features but caused catastrophic failures for some users. Changes to iCloud caused data loss, and those losses were synced to those users’ Macs via iCloud.