Pretending that there was nothing important on this laptop. Doing a clean install of Yosemite. I will not regret this.

I did it w/o a hiccup.

You erased your entire hard drive first?

Nope

Actually have update the OS a couple of times since I got the Mac & haven't had a problem at all. I did run outta memory on the phone so had to put music in the cloud & back up the phone to update it, then restore it, but it all worked like it was planned.