What the common man things of PTSD? Most certainly yes.
A startup world isn't a literal warzone. The experiences of a startup can be extremely negative, but aren't anything near as bad as what a soldier sees - so lets not get these things confused.
But anyone can experience trauma from anything. Be it a loss of someone you care about... or a horrifically bad boss. Extreme stress be it in a warzone or in a startup is still stress. It's hard on the body and can cause a lot of negative reactions in the short or long term.
My experience was mild in comparison. Got a new boss at a high stress, high growth, no-life startup job (the kind where you boast that you work 80 hours a week, 6.5 days a week minimum). He was terrible, I started to look for a new job but it was slim pickings at the time. Eventually I did get an out but for the first two weeks after I left, I had nightmares every single night about that boss. Continued to happen less regularly for quite some time after that.