An older FiST driver chiming in here:
When I was younger, I changed cars a lot because I could only afford (or had space) to have one at a time, but I figured life was too short to spend a long time with any one car. It was rare that I kept a car more than three years. Later, I finally got a car that felt perfect for me--an '04 SVT Focus--and I kept it for seven years, and the only reason I traded it (on a Mazda2, big mistake--same platform as the FiST, so laughably inferior) was that I was tired of its many problems that were not quite catastrophic but were unusually expensive to repair for an "economy car."
But I regretted not keeping that car almost every day since...until I bought a '17 FiST, which I love even more than the SVTF.
If this car proves to be dependable (so far so good after 12K), I can imagine happily driving it at least 10 more years (I don't put on a ton of miles--maybe 8K a year). I think when you get older and find a car that feels right for you, you're more inclined to want to keep it as long as it's practical to, and not start wanting newer and/or faster things. My hope is to keep the FiSt long enough that if I do decide to sell it eventually, it'll be a Bring a Trailer-worthy car at that point and fetch a decent price.