I haven't had to log in for months and months even when I've shut down my laptop, maybe because I never clear caches etc etc ? In fact I don't understand what you mean.
Sometimes I can shut laptop down at night ( I never sign out ) and when I come back in the morning I am still signed in,
and other days I have to sign in over and over again, dont know why, its a mystery. X
FWIW I have to sign in everytime I visit if I want to ask a question or reply. I have looked and can't find a 'keep me signed in' option, just a 'remember me' option which is ticked but everytime I visit the site I am signed out -even if my PC just goes to sleep, when I visit again I'm signed out.