[Viliam1234]

Yeah. At some moment in my life I noticed that there are two types of "friends": First is a person you can have fun with... and that is all you can ever do with them. Second is a person you can have fun with, but you can also discuss serious things with, and help each other. As long as you only have fun, these two types seem similar. You typically learn the difference only when something bad happens to you... then the first type of friend disappears.

You can filter friends by putting yourself together in difficult situations on purpose. Like, take a long trip together, some problems will happen and you can see how the other person reacts. Or volunteer for an organization that helps others; the friends you find there are already filtered for their willingness to help others. (This isn't a 100% certain strategy; there are some abusers who know that others use this algorithm, so they go there fishing for easy victims to exploit. But most of lazy and selfish people would refuse to try anything like this.)

If your life is all about fun, then you are at risk of being surrounded by people who are your friends only as long as the fun lasts.