Yea, I chat with ex-colleagues about their work and how they're faring since we've worked together.
I'm a director of eng. as well, so there'll be times when I reconnect with former managers and reports and provide/get mentorship that way as well. The key is to actually keep in contact and in touch beyond any singular job; if you were able to mentor them while you shared an office, that relationship is still valuable afterwards. Of course, this means that you have to develop the skill & reputation to be a good mentor to others around your job.
I'm a director of eng. as well, so there'll be times when I reconnect with former managers and reports and provide/get mentorship that way as well. The key is to actually keep in contact and in touch beyond any singular job; if you were able to mentor them while you shared an office, that relationship is still valuable afterwards. Of course, this means that you have to develop the skill & reputation to be a good mentor to others around your job.