Best of luck with the move!
I'm not exactly weighing in because I think Anthony covered it all pretty well there - and yes, humans do need things spelled out for them repeatedly, now don't they, gotta love the brain and it's tendency to supplant other information in place of what we thought we already learned.
Anyway, I read a blog post where the author was upset about over use of the word "trigger" that's now occurring in general society and people claiming because they're "triggered" that they must have PTSD. I reiterate, PTSD is a disorder which runs a gamut of symptoms, which cannot all be "triggered" at one time.
On a weapon (sorry if this is triggering to some) you pull a "trigger" and the reaction is the release of a firing pin and subsequent release of a bullet - I'm sure it's way more complex than that but this can demonstrate use of the word trigger. Something when activated causes a reaction/response. Plain and simple. The term has been used in general society for some time but it's use was never really popular, until the advent of its association with PTSD.
Anyone anywhere can be triggered to something, it is not exclusive to PTSD, it's merely a tool that helps us understand the nature of the reaction we're experiencing. This is why my therapist made it a point to demonstrate that there are different types of triggers and they're not exclusive to PTSD. A trigger to anger is something that makes you feel instantaneously angry - its an "emotion trigger". A trigger to trauma is something that makes you feel afraid/panic/anxious and starts the physiological reaction to the stimuli, be it auditory, visual, scent or taste.
In this way, yes, you can "trigger" to positive feelings and memories. I like to purposely seek out these positive emotional triggers because they are actually good at helping me cope from day to day.
A trigger is not exclusive to PTSD but the concept is used widely in treatment as an easy way to help us understand what we're going through.