There's a bot on reddit that you can set a time for and it will remind you when the date arrives. That is the remind me bot, in a long line of all kinds of different bots that can be triggered/summoned/whatever.

When bots pop up in reddit threads, usually they are met with a "good bot" or "bad bot" comment depending on what their response is when summoned.

You, as a person, responded to my comment, in a response that showed you clearly missed what was going on. I'm going to be dead in far less than 100 years, let alone 500. Requesting the bot to remind me was a bit pointless and meant to be a joke.

I responded with "bad bot" as another joke, which also missed apparently. And now you know, and the joke is ruined, due to having to explain it.

TL/DR: r/whooosh