Uploading???

I do not recommend messing with one’s Mac Photos library. I created another (I won’t go into why); found I couldn’t do what I wanted with it (turn on iCloud Photos) ... because insufficient space WHAT THE F SWEAR WORD?!; went back to the original library; couldn’t turn iCloud photos back on because insufficient space (OH MY F SWEAR WORD GOD WHAT NOW?!?!).

Kept my head, thankfully. Agreed to switch the library without turning on iCloud Photos. Then clicked the box to turn it on ... and it worked, thankfully.

Then ... it tells me it’s uploading seventy-something thousand files. WHAAAAAAAAAAAT

It didn’t. It completed the operation far too quickly for it to have uploaded them; it must have just checked them all - and would have uploaded anything that wasn’t synced.

Don’t. Mess. With. It. ;)