You say "just" like the following text isn't entirely incomprehensible to anybody not already familiar with obscure internet lore.

I've been online since 2000. I do not know what any of this means. I know "moot" means "mutual" these days, but judging from how old rickroll is, I bet "moot" didn't mean "mutual" back then because "moot = mutual" is actually a Tumblr thing.

take this w a grain of salt i could be wrong but iirc:

-4chan moderator named moot created a word filter that turned all instances of the word “egg” to the word “duck” in the mid 2000s (2005? 6?)

-in a thread discussing egg rolls, this created the term “duck roll”. someone posted a picture of a duck in roller skates in response to this.

-links to the “duckroll” image were used similarly to rickrolling now

-the rest is pretty understandable

[ID: A comment from kaiasky, reading “isn't it just moot s/egg/duck -> duckrolls -> duckroll image -> 'rolling' becomes a synonym for fake links -> rickroll'd”. End ID.]

Close enough.

Moot is the creator and owner of 4chan (which he created when he was 15), not just a moderator.

And the duck roll isn’t wearing roller skates, it’s got monster truck wheels

I still don’t understand why the filter changing egg to duck came about.