PTSD left untreated or undiagnosed/misdiagnosed is devastating. Soldiers who return from combat have been known to avoid large malls and box stores because of the open spaces with no cover, and they have been known to refuse to go to see fireworks on U.S. 4th of July celebrations because of the sights and booming noises. Too many triggers.
It's much the same with rape survivors. I once worked with a woman attorney who was repeatedly drugged by her law partner, and leaving her oblivious to how she wound up being gang raped by a small group of men. She was gaslighted to the extreme, waking up amidst being raped, and then dropped off at her home telling her she was imagining things. She endured that for well over 6 months if the records were correct, but she wound up moving a couple hundred miles away closer to family with the help of the FBI and local law enforcement, and changing her name so she couldn't be found. The authorities had been attempting a sting operation to infiltrate this ring because she was not the only one being prostituted out without being fully cognizant of what was going on, and it was an underground illicit drug ring as well.
She couldn't be in the same room with other people with bare feet. She could be alone bare-footed, but anywhere else where she's inside somewhere and more than one person because barefoot, she starts to panic. Again, plenty of cognitive behavioral therapy techniques help her to cope, and especially if someone is there to guide her back to what she's seeing, sensing, hearing, feeling right there at that moment, and not what was happening many moons ago.