Good idea to re-make acquaintances with long lost friends?

As I get older, I find myself getting nostalgic for past times and old/ childhood friends to the extent of Googling and looking them up on Facebook etc. I’m guessing this desire to relive the good ol’ times may be a bit self-deluding at some level – but is it generally a good idea to reach out and get back in touch? I’m uncertain coz surely we have all changed over the years… memory is a strange thing & I may not even like what I’d find