I think it's fair to call me an elder lemming at this point, as I recall the reasons for both. I signed up on .world with my first account on the last day before the infamous APIocalypse.

Along with myself, a lot of us were putting effort into posting good stuff, upvoting, and generally having a lot of positive interactions. Someone on !lemmyshitpost@lemmy.world posted a picture with a can of beans with a caption along the lines of "I hear that lemmy will upvote anything. Here's a picture of beans". It quickly became the most upvoted post of all time.

As lemmy culture developed into a deeply political space, it began flooding !lemmyshitpost@lemmy.world with American politics. People got sick of it, and people started doing "we're posting x now until politics stops". There had been a couple rounds of various themes, and then someone announced "that's it, I'm sick of politics everywhere. We're posting corn". Cornposting has become the default political purge over there.

corn, beans and squash are known as the three sisters

history will say they were roommates.

about the beans: look for top all time
After the wave of newcomers lowered lemmy started to have some "weekly" phases where other memes became the meta like the german pedalo or moths and many others.

But as a moth fren i bring some moth memes back from time to time :)

If someone could also explain why half the post titles have the word "rule" in them, that would also be helpful

Corn is out. Squash is the it thing now!

I was sick of seeing political stuff on the shitposting group so I started bombarding it with corn until it stopped. I had happened to have a bunch of corn pictures saved on my phone because I had flooded my friend's discord with corn pictures just to goof on her.

It spiraled into a glorious corn filled nightmare insanity, and as someone from Ohio, I appreciate that.

I think the beans came up later because people like to play with themes.

Lemmy just loves bean corny

Don't forget about no pooping!

Two of the pinned memes on slrpnk memes tells you exactly why we all love corn and beans!

have you never beheld a sweet, buttered cob

ASK THE MOTH. THE MOTH WILL TELL ALL!

We are simple farmers around here, the common clay of the internet.

I'm Captain Jenks of the Horse Marines

I feed my horse on corn and beans

It’s earlyish internet culture not Lemmy borne

2 of the 3 sisters

Hexbear has been Beanis posting for a long time now. I don't know how it started, but it's a significant part of that instance's content at this point