Some Hindu philosophers estimate that the universe repeats itself every 311 trillion years or so. Modern scientists such as Sir Roger Penrose have lent credence to this basic idea, though with less precision. Everything that happens, it seems, is likely to happen again and again and again. I find this vaguely comforting.
What I find less soothing is the many things that are endlessly repeating within the brief interval of my career in computing. You can read about the latest of them here, on my Mimecast blog.