You grow up playing games with your childhood friends, watching movies and music videos, reading those comics, dancing on songs and many more things.
Years after when you happen to come across them you become nostalgic and you say “Oh! This we used to watch/do when we were in 5th grade” or “this was the best comic of our time” or may be “nowadays kids don’t play like we used to. We used to have so much fun playing on grounds”. Or for that matter “the music videos of our time were really beautiful and decent. Nowadays they don’t make such videos. Alas!”
You can find people sharing old songs and videos on FB, sending emails with old commercials and sometimes playing same old games again with old friends J Cherishing good old days.