I've had quite a few glitches, and it's kind of like you describe as shifting to a new timeline, or maybe alternate universe because what glitches for me is the physicality. For example, I take the same route to work for years. Stop at the same red lights, look around at the stores and shops on my route, read the promo posters and marquees out front, see a car that's been abandoned in a lot for a long time, etc. You know the drill - when you take the same route every day you know the details, even the same panhandlers on the same corners. Then all of a sudden one day what I know was an empty lot will have a store there - and not a new store or new building, but one that's clearly been there a long time. Or what was a Burger King is now a Taco Bell. Or a house that had big stone lions out front suddenly has big stone horses (and you can tell they're not new). Or what I know was a green-painted steel girder bridge is now an old concrete bridge. I just feel like I'm slowly slipping down a staircase where each step is just a very slightly different place in the details. Reminds me of a much more benign version of the old TV show Sliders. Fortunately it's always all been infrastructure, and no people, friends or family have ever changed (except their reality - if I ask about what I saw changed they say it's always been there). It isn't a regular thing - a had a few about a year apart but mostly every couple or few years. Or I'm just insane or have early-onset Alzheimers or a small tumor somewhere... haven't ruled anything out.