Do you get attached to people?

I think the level of attachment varies depending on the depth and longevity of the friendship. I met my best friend when we were 18 and I'd say I'm pretty attached but I also have some more recent connections that run pretty deep. Others are less profound so I guess I'm less attached.
If you aren't getting attached at all, maybe you aren't investing in the friendships... Possibly to protect you from feeling pain of the person leaves your life? Just my thoughts