I was pretty torn up about it in the months leading up to leaving - I'd lived there for 9 years - but it helps that Toronto's such a great place to be.
I lived in the SF South Bay Area, aka Silicon Valley. It's about 40 minutes south of SF, and the environment is mostly tech campuses in a collection of small towns. E.g. Cupertino, Menlo Park, Sunnyvale, Palo Alto, Mountain View, Redwood City: each of their downtowns were maybe the size of Kerrisdale, and each of them are about 10-15 minutes of driving down the highway. Never too far from the mountains and Pacific Coast, where a good drive or ride could be had on the weekends or after work.
And the access to world class tracks!! Sonoma (Infineon) is an hour north. Thunderhill is another hour up. Laguna Seca is 2 hours south. Buttonwillow another hour down. Between my S2k, R6, and R56 Cooper S, I'd been to 25+ track days.
It was also great to be within an hour's flight to LA (we used to drive there, but it really wasn't worth burning up a whole 5 hours each way for just a weekend). The food there is great, and there the beaches and warmth are really California as advertised.
I liked it but I missed living in a bigger city. I suppose I could've gotten that living in San Francisco: some of my colleagues took the company shuttle to and from every day. But SF's a little grungy these days, esp after COVID.
I also got kind of sick of the continuous sunny blue skies. When every day is the same, it all just kind of blurs together. You're less grateful. It doesn't feel special. I missed the seasonality of Vancouver. I missed the rain, I missed the snow.
But the work life: wow. For engineering, it is the major leagues. You get really good at what you do, because you work with the best, they expect the best, and the challenges are numerous and fun. You patent. And you get access to work on some truly bat-shit crazy stuff that only SV has the resources to fund. The pay is pretty ok too: you look around in the parking garage and it seems like 911 Carreras are rare to see, only because there are so many GT3s lol.
Anyway in the end, I moved for family. It's kind of hard to let go of the work responsibilities to really be present for your kids (my colleagues try, to varying degrees of success. it takes a lot of willpower to drop what you're doing and skip out on stuff, when you know it's going to let people down). Also my wife's family is all here and we wanted the kid to be among family. She also has a career that she loves here and we feel like it's her turn to see how far she can go. So when I finally shipped the hardware I was working on for so many years, we figured it was time to go.
P.S.: Silicon Valley the show is way exaggerated, but it has some basis in truth

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https://www.youtube.com/watch?v=A-b7-fLOjlY