A peculiarity: I'm almost never logged in to websites
Over time, I've come to understand that normal people are almost always logged in to a whole host of big websites out there, even when they're not actually using them. Facebook, Twitter, Flickr, LinkedIn, Google, and so on and so forth, all of these pervasive behemoths that many people sooner or later wind up with accounts on (undoubtedly plus many other sites).
As you may have guessed, I don't do this. I especially don't do this with behemoths that have their tendrils of social buttons stretching across the Internet because I don't trust them. The only sites I'm willing to stay logged in on are ones that I trust a fair bit (and generally also use a decent amount). On top of this, my regular browser is so heavily protected from being infected with cookies that it's often easier to use my testing browser or Incognito Chrome for logins on new sites; as a consequence I wind up effectively 'logging out' when I close the browser and the cookies are discarded.
Among other effects, this sometimes gives me a skewed perspective on using popular sites, especially sites that I'm a member of. For instance, when I look at people's Twitter profiles in my browser I'm sure I'm getting a somewhat different experience than I would be if I was logged in. One of the differences, relevant to a recent issue, is that I cannot accidental betray to a website that member X followed link Y from social media, unassociated email, or whatever.
(Twitter is actually an especially interesting case of logged in versus not logged in because of how blocks work. If someone with an open account blocks you and you're logged in on Twitter, you apparently can't even look at their profile to see their tweets in your browser, although if you log out you can. Of course it goes the other way too; if I'm not logged in I can't see into private accounts that I do have access to through my Twitter accounts. This sometimes matters because looking at tweets in a browser can be the best way to see the thread of a conversation.)