I ask this because when I look back on some of the friends I had back when I was a witness, they were so much work (not all). Plus a lot of them were rather nerdy / sheltered. Not that I thought myself as uber cool, but I was street smart and had to grow up early in life and had a few responsiblities on my plate. A lot were sheltered and kinda clung to me like a limpit to a rock because I was the one organising events, I was the friendly one and would accept all sorts in to my group, and to an extent helped them grow in certain aspects.
I only made friends....or rather they made friends with me simply because we were witnesses and were "lumped" together. Attended the same junior/high school, same congregation. It's only obvious that you are going to start forming a bond. If I met the same kind of people now I probably wouldn't make friends with them. Bar for the faith we didn't have all that much in common. Many times I would feel so drained, like they had drawn the life out of me. Constant upkeep, constant encouraging, building them up... no one really returned the favour (not that you always want that - but friendships are a 2 way street) I was always giving giving of myself. I had to be the strong one in the crowd. It's saps your energy.
Now I look for friends that can function on their own and don't need to pampered / looked after / or are negative.