I'm 55 and I have mostly worked for three companies in my life: Penn State (10 years, started there 1990), Raytheon (3 years, started 1995), and a small hedge fund (started 1996, 12 years). I haven't worked for Penn State for about 4 years and I have lost touch with about 80% of the people I worked with there, but I still feel a strong bond to them. I have not worked at Raytheon for 15 years, and I've lost touch with 98% of my friends there, but every once in a while I do reconnect with them. I still work for the hedge fund and I do keep in touch with 50% of the people I met there even after they have moved on to other endeavors or retired. About half of my long term friendships came from work relationships.