Things usually don't turn out this way until after I make a post saying that things are going well so far, so why isn't that the case this time? :(
Also, a meme I got from cactus_rs:
"five of my icons, explained. If you want to expound on five of your icons, comment and I'll pick five for you."
I hope I end up doing this right... Anyway, cactus_rs chose:
This is from the X-Files episode "Pusher" (season 3, episode 17), which is about a man who can bend people to his will. The above userpic comes from a scene where he gets past FBI security just by writing "PASS" on a piece of paper and attaching it to his shirt in lieu of an ID.
I tend to use this userpic whenever I just finished something - or passed it, if you will. Usually the "something" is a difficult assignment, but sometimes I use this userpic just because I beat a video game.
Speaking of video games...
This comes from the intro of Super Mario Galaxy 2. I don't know exactly what "ΔΧΧΔΔΧ?!" means, but it is the first thing this Luma says to Mario in the game (even though Lumas speak English throughout the entire first Super Mario Galaxy and even most of SMG2). The stray "?!" in the top left is from the same quote - I intended to crop it out of the screenshot and retype it for the userpic, but it ended up partially still there.
My uses for this vary. Sometimes I use it because I can't understand something. I think I've also used it sometimes while talking about Super Mario Galaxy 1 or 2 in general or while talking about the Greek alphabet (since those symbols resemble the letters delta and chi), and I think I even used it once while talking about the Cyrillic alphabet (even though it doesn't resemble Cyrillic as closely).
A hypercube (or tesseract, or four-dimensional cube, or whatever you prefer to call it) that I drew myself.
I don't have much else interesting to say about the userpic itself, so I guess I'll say something that's only somewhat interesting about it (which you may skip if you like): It's hard to tell after I mixed the colors together, but all 8 of its cells (cells are to 4D shapes as faces are to 3D shapes) have individual colors, and most sides' colors are roughly the opposites of those on the opposite sides. Red and cyan are on opposite sides, blue and yellow are on opposite sides, and green is on the top while pink is on the bottom, though the left and right cubes are purple and orange, which aren't quite opposites.
My uses for this userpic are somewhat random. Obviously, I almost always use this userpic whenever I talk about the fourth dimension (or other higher dimensions), but those posts are actually less frequent than the existence of this userpic would imply. Sometimes I use this userpic for other math-related posts, or for color-related posts, if I don't have any other userpic that's more closely associated with the post. Also, at some point early on, I started a trend of using it on posts about finishing difficult assignments; I don't know how it became associated with finishing homework (since the most difficult assignments for me usually weren't math-related), but it stuck until I finally made my "PASS" userpic. I've probably used it (or any of my userpics, really) for reasons besides those as well.
Another X-Files userpic, this one from "Bad Blood" (Season 6, Episode 12). The events of the episode are told from Scully's point of view and then from Mulder's point of view (with hilarious differences between the two retellings), and this userpic comes from a scene in Scully's retelling in which Mulder's "breakthrough" is when he notices this (except the full quote is "Have you noticed this man's SHOES ARE UNTIED?!") about one of the killer's victims.
I don't get to use this userpic very often, but I did get to use it a few times in a conversation in asperger
At some point, on some website I don't remember, I found a slideshow of pictures of funny road signs; I don't remember any of the others now, but one was a different upside-down speed limit sign that said only 20 (02?) miles per hour. I was inspired to make a userpic out of it, but since I couldn't find that exact same picture again, I went with the closest picture I could find - this one.
I use this userpic the most whenever I talk about driving, but it would also make a good userpic for talking about upside-down stuff :)