The only time I find myself getting logged out when I don't actually log myself out are occasions when I close my browser.
It's not everytime I close my browser, but half the time, yes. Of course, part of it is because I can't click the "Remember Me" option, because if I do, then, if I do logout and try to login into Gmail (which is a separate account), it still thinks I'm logging into my GroverKent YT account, which isn't my Gmail account. Similarly, if I click "Remember Me" when I login my Gmail account (which also contains my official YT account), then likewise, I try to login to my GK YT account, but it keeps logging me back into my Gmail account.
So yeah, everytime Google claims they're simplifying things for us, they're really just making it all the more confusing, annoying, and complicated for us.