Actually, you need to meet people who are also open to making friends. But it depends what sort of friend you're looking for. Sure, you can make shallow friends

Actually, you need to meet people who are also open to making friends. But it depends what sort of friend you're looking for. Sure, you can make shallow friendships/acquaintances by just mixing with people regularly, but if you actually want a deeper friendship you need to meet people who have the time and inclination to put in the effort involved. This typically happens when you hit transitional points in life where you feel alone and want a group to belong to (e.g. school to college/university, into your first job away from home with a group of other new starters, mums having their first child, etc). School, university, starting your first job with a group of others at the same time gives you ready made friends (provided you can sit next to them). Friendship is basically a function of time and proximity. This has been shown in several studies and is accurate by my own experience anecdotally. Meeting people who already have a social circle or all their time allocated won't be conducive to making deeper friendships. Once you're in the world of work, going from one job to another, it can suddenly be very difficult to make deeper friendships, especially those that will endure one of you changing jobs (if they're colleagues).