It's great to run into an old friend such as the one you describe. You sort of just pick up where you left off as if the years were just a comma in a long running conversation.
You aren't often able to make friends like that as you get older. Theres only a certain number of years when you are an open book and have time to invest in forming close relationships. More is the pity (for me anyway) that our opportunities to make friends was limited to whomever happend to be in the same kingdom hall we attended. More often than not, there were very few to choose from....and anybody we liked from say, school or work was off limits and we certainly didn't know anybody from a sports team or club.
Most people I work with have a lifetime of friends they've gathered from school, work, clubs, sports, church or friends of friends, that stuck with them through all their liffe's changes. They weren't required by the authorities at their old school, job or club or by their mutual friends, to drop them because they changed their view of religion.