I also need something that will stop me from making pony references when talking to people.
This... may not do that. If you get far enough in... well, you'll see.
My own experience may be relatively common. I kept seeing these avatars of weird gray people, and wondered what that was all about. Somebody referenced MSPA, (in a discussion about pumpkins, IIRC) I checked the site out, and read a few pages of Homestuck, got sidetracked by a link to JailBreak, and read that instead. Then Problem Sleuth. Then I forgot about Homestuck until I ran across the page on TV Tropes, which had a lovely picture that piqued my interest. I decided to go back and at least read until that happened. A few pages later, and the sound kicked in. Then flash animations. I was officially hooked with the second major flash, (The one with the deserts and the Explore soundtrack) which hinted that yes, things were going to keep getting more epic in scope. I finished my archive binge a few days later, somewhere during the Doc Scratch hosted segments. Along the way, I discovered that about three hundred more avatars I hadn't previously recognized suddenly became recognizable.
So yes, I'd say it's worth it to read it. It's a sprawling modern fantasy with a lot of site in-jokes, (Most of the beginning with John putzing around in his house is pretty much just the usual 'this is
you playing a weird video game' premise that the others ran with, and it definitely helps to at least skim the other stories on the site.) so if you were enough of a fantasy reader to read the Wheel of Time, you should be fine reading this.
As for people looking over your shoulder, I'd expect one of two reactions:
1) "Oh, hey, Homestuck! Have you gotten to the part where *massively spoils a part you haven't read yet*?"
or
2) Them: "Huh, what's going on there?"
You: *Briefly explain what's going on onscreen*
Them: "Why are they doing
that?"
You: "Uh, it's a
long, complicated story. Got a few hours?"