Take a calm, pleasant moment to think about your most cherished piece of media: The magical movie, bewitching book, scary song, terrifying theater performance or vaguely spooky video game that has touched your soul in a way that nothing else really has. I bet that, like all people enamored by non-transient forms of entertainment, you've enjoyed that piece of media more than once.
There's nothing unusual about wanting to revisit familiar favorites; it's fun to relive the adventure, to meet the characters again, to notice things you haven't before while looking forward to the parts you loved most. In a world already filled with more media than you could possibly enjoy in your humble human lifetime, and with a ceaseless discharge of ever more content barraging us from every possible outlet, it can be comforting - even therapeutic - to return to an old darling.
So, how come we don't feel the same way about TTRPG adventures?