Hmm. I have had a lot of great memories on Prism. I think my favorites are the times when I laughed. Some pretty funny things have happened before. It is difficult to remember the specifics though.
My least favorite memory? I am going to say when you got muted and when I finally enchanted diamond gear in the new world, only to burn it all in lava. For anyone who is interested, I then grabbed some other diamond gear, died again, and lost my /back by accidentally teleporting home instead. I started fishing after that. XD. I think I tried to enchant some gear again and burned in lava a second time. How does that even happen? XD. I am extra cautious now...