The scents which most remind me of home are a Ralph Lauren perfume, incense and spaghetti. They make me think of when I would sit at the table, listening to CBC Radio and playing my Gameboy while my mother cooked and tried to force me to listen to her cooking lessons. I never did learn to cook but these things remind me of good, serene times in my life. Sometimes though, I'll smell or feel or hear something that brings me back to a place a lot less warm. Sometimes it will be something as simple as sitting in the backseat of a cramped car or other times it will be when I look into the mirror and see the eyes I inherited that will bring back awful memories of a person I both hate to think of and almost never stop thinking about with each waking moment I have. This is part of my PTSD.
I don't entirely know exactly what moment sparked it or if it was a collection of moments because my memories are tainted or missing. Almost half of my life I can't remember and the rest is trying to piece together the truth - something I'm never sure of. This is not because I am paranoid but instead because I was brainwashed as a child by someone I should have trusted. I was hurt by them in ways I'm not sure of entirely. I've thrown out every photo I own of them too but still their face is as clear to me as the computer screen in front of me right now. I'm not alone in this too.
As I'm only 22 there is a lot of stress that goes along with your mind playing tricks on you and how it tries to combine with senses and emotions to give you hints as to what really happened. As I'm only 22 this stress is amplified because I'm trying to find myself as every young adult is. It's enough to make a girl feel like Raoul Duke. 
Learning to cope is something that takes years to do - learning how to recognize the symptoms for each person can take a while because you are constantly bombarded by things that might remind you of things if you don't have PTSD due to combat because you haven't been physically removed from the place where your trauma happened - at least not in an international sense of the word. Maybe you've moved houses or cities but for the most part the difference within a country isn't night and day. It is more like night and later that night, if that. The people still have the same accents, have the same colloquialisms and do generally the same things.
The change in place is key to living with less flashbacks - they won't go away entirely but they do lesson with the least amount of familiarity that you have. This is why I travel and why every one who has PTSD should too.
When I travel I create new memories for myself. I collect them like someone might collect coins. When I travel I am able to have a weight lifted off my shoulders because my fear is replaced with excitement for the newer and better adventures that come with travel. I am able to feel free from the deep sinking pit I always find myself in when any one of my triggers might arise because I don't have any in places I've never been to.
When I was bathing elephants, partying until morning, dancing in packed salsa clubs, or even just taking a train further away from where I'd ever been I didn't have any flashbacks. I didn't even worry that I might! It's practically unfounded back home where people with PTSD, myself included, have to learn to bring themselves back to centre from a flashback or dissociation. The new experiences simply don't give you that sense of dread which makes you feel like you're in Fear and Loathing in Las Vegas at times.
When a person with PTSD travels it saves their lives. When a person with PTSD travels it gives them hope that one day, back in their home country, they won't be constantly afraid of having them because the frequency is so low abroad. When a person with PTSD travels it gives them a much needed break from the hard life they have so obviously lived.
This is why I travel and why I encourage others too because before I had left for my first flight I had never thought that this sort of life was even possible to live and the hope that things could get better for someone with PTSD is very important.
If you, or someone you know, is living with PTSD travel is the best fix there is.