Yes, it’s when the normally reasonable, well-mannered, soft-spoken and together kind of people lose it that you’d better watch out. It can be awesome to witness, as you well know!
I haven’t seen this at work, but when I was in my mid-teens, we lived in an apartment in the same building and stairwell as my paternal grandmother. My parents originally bought the apartment from my grandparents when they were downsizing and a smaller apartment became available on the floor below, which was helpful because the building doesn’t have elevators (to be fair, it’s only 3 floors of apartments with garages and above-ground storage on the ground floor, so not onerous for an able-bodied person). The larger apartment was used to store our furniture and most of our possessions while my parents who were scientists (my mom was my dad’s research assistant for many years) got grants to work in the UK for a year.
But because she’d lived there before and because she’d kept an eye on the apartment and watered the plants regularly during our absence, she had a key. Granted, my parents also had a key to her apartment, but they never used it without invitation for as long as she was merely unreasonable rather than suffering from dementia.
My mom, who had a troubled relationship with her MIL because no woman was good enough for her precious son, her only child, very rarely loses it with anyone, including me and my sister when we were growing up, but you’d better watch out when she does lose her temper.
Anyway, one day grandma walked in without even ringing the doorbell when my mom was in the middle of complicated dinner preparations (we were expecting guests from mom’s side of the family and grandma wasn’t invited) and my younger sister and I were helping with the prep. Mom was stressed and lost it. She didn’t yell, but she hissed like an angry cat, and wore an expression to match. She confiscated grandma’s key then and there, and told her in no uncertain terms that she’d better not visit without an invitation in the future, and all but perp-walked her to the door. My sister and I stood there open-mouthed. I can’t remember where our dad was when this all went down, but he got home before our guests arrived.
For much of the rest of the meal prep, our mom kept muttering under her breath, but she was the perfect host by the time our guests arrived.
To our grandma’s credit she was a wonderful grandparent, and to my parents’ credit they never resented that, even if my dad also had a somewhat difficult relationship with his mom. But at least that meant that he always took my mom’s side in her arguments with her MIL on principle, regardless of what he actually thought. And probably much to the dismay of his mom…
A few months later, grandma woke all of us up in the middle of the night by ringing the doorbell until my parents opened the door. I heard some of the talk and apparently grandma was afraid of the (non-existent) strangers who’d showed up in her apartment. She’d always had a somewhat difficult personality, but this was the first sign of actual dementia that I can remember. Her cognitive capacity deteriorated quite quickly after that.
