For some reason, safari seems to want to nuke SOME of its cookies from time to time. Especially when I restart the machine. It doesn't nuke it ALL, though. But I keep having to sign in to a bunch of stuff and it's getting on my nerves. Sometimes I'll have a gmail tab and a Facebook tab amongst my open tabs, and all of a sudden those pages will seemingly "log out", and I'll have to sign in again. Out of sheer desperation, I nuked my entire OS X installation last night, and on a fresh, clean, untarnished OS X installation, it's still doing this. Any ideas what the hell is going on? 2013 15" rMBP El Capitan. Any ideas?