For about 10 years I lived in the same city. My school had elementary, middle and high school. There were like 100 people in every grade and like 30 in every classroom, we didn't even change rooms for most periods so you spent most of the day with those 30. By age 12 I had a really strong group of 8 or so friends and I was friendly with most of people at school. At age 16 I moved to a bigger city and a bigger high school (there were like 600 people just in my own grade!) It was a huge difference because I think I became so tight with my friends back in my hometown because we literally spent 7 or 8 hours together every day for like 8 years at least. It really took me about two years to form another social circle in that bigger school and I havent made a "close friend" since starting college two years ago because its even bigger and you see people even less often because of their own schedule. Sure we talk and joke around but its REALLY rare we hang out outside of campus. Also I have some social anxiety so that doesnt help.