Yes my situation is opposite. I dont ever recall logging into YouTube yet I was. First time it asked me to login again I had to reset the password cause I had no idea what it was.
It randomly asks me, on other sites, to login again, even though I never log out. More and more sites are doing this just to verify that its really you.
One does have to watch for suspicious ones though such as a site asking you to login using say your FB credentials for their site.