The tie that binds; the cord that connects.
Climbing partners are life-long friends, especially one's early partners.
The climbing partners that survived the "apprentice" years with you remain your closest buddies even if you don't climb with them any longer.
People who climb together have a certain connection that's difficult to explain to other folks.
Sure, climbing rock & ice is great fun. Traveling together to the mountains, the first beer after a tough day at the cliffs, seeing a woman on the rocks (in the early days, ~1980's, that was uncommon), all add to a strong friendship.
But it's the tough times that seal the deal.
Holding a long leader fall, surviving a 100+ mph winds/-40F below bivy together, wondering if the belay anchor is going to hold, down climbing in the dark with no headlamps or moon, this is what makes climbing partners stay "roped up" thru life.
So give your old climbing buddy a call sometime.