I have always had a 12 month turn-around. Even when I lived in Tennessee and was living 5 min from my university, I moved apartments EVERY.YEAR. The only exception was when I moved into a house the end of Uni where I stayed for 18 months.
Once I left my family home, I was on the search for something new and exciting. The fact that there were so many places to be and so many places to live exited me like no other!
This was only made worse when I learned about Couchsurfing after I came back from a month long study abroad in Argentina. I had the full blown travel flu and needed options. Couchsurfing opened that world for me and it didn’t stop for 5 years (and still hasn’t).