To think it's sad but normal that many friendships drift

I think you just have to move on, make new friends.

I have a number of “ situational friends” over the years, three from school days, though we have not been in touch since Covid. I had no reply when I tried to make contact.
I have a group of friends from university and we have kept in touch, met up occasionally. We just pick up where we left off.

Nowadays I have acquaintances I know through choirs or church.

I agree that sometimes the people that you work with although you think of each other as friends when you leave the workplace you then find after a few years those “friends” were nothing more than work colleagues! I have a small circle of what I term as real close friends whom I’ve had in my life for over 25 years

So where would we be if we kept in touch with every friend we’d ever had ?
Can’t be done.

I'm an odd bod. I don't feel the need for friends. Maybe it's because I'm close to my sisters. They are the same. Of course we have friends, but it wouldn't bother me if I didn't have mine. Sounds awful I know.

I agree Vintagejazz, re your assessment of some friendships.

Unfortunately, unless you really click with someone, the friends you meet at school, work, etc...don't typically last.

There's actually a name for these types of friendships: 'situational' friendships; bound, as you said, by seeing one another only in certain situations.

Typically most people only have, or feel the need for just a few true and close friends.

You can be friendly with many, but real friends with only a few, especially hard on the young, and the elderly, in these days of mobility and change.