Htydjtk

I strolled along and met a fellow.

"Hello," I said.

"Hi."

A few steps later he began describing...people, I think?

"Well, you know the one."

"I do?"

"Yeah. Yellow hair, red jacket, likes that one guy named Sissel."

"Sissel?"

"Yeah, him."

"Well, who comes second?" I asked.

"Hmm, what do I say? He kind of looks like a short cafeteria with a Cyanocitta cristata painted over the front."

"Ah, him. Who else?"

"Well, he's got a diamond and a name like a politician - senator, in fact."

"Hey, don't bring politics into this."

"Oh, sorry. Figured it'd be the easiest way for you to recognize him. Next one's easy though. You ever seen a flat die?"

"Ahh...yeah, sure."

"Now give it six sides."

"Isn't that just....oooooh. Clever. Got it."

"Next fellow's pretty famous - his reputation precedes him. Matter of fact, he once got an email from that Void guy."

"The Void, the one that - ?" I started to ask.

"No, you've got it all wrong. It was a void."

"Oh. Who's sixth?"

"Well, he got mistaken for a drum, once - you won't find a good source for that, though. Then he had that one time - you especially would remember - the three-piece thing."

"Oh, yeah, him! Good guy, good guy. All good guys, really."

"And gals."

"Well, yes, but...I...they...who's next?"

"Not very inquisitive, this one."

"Shy, perhaps?"

"Not exactly, although he did define that word once."

"Ah, yes."

"The next person is, of course, a very handsome and charming fellow."

"Oh? And that is?"

"You, described sarcastically."

"Well, I'm flattered."

"At least he's funny."

"Thanks."

"That was still sarcastic."

"Ouch. Who's the ninth person?"

"You like to fish?"

"I do." Very relaxing, I find it - sorry, PETA.

"What do you catch, here in the US?"

"Weeeeeell...." I said, mentally checking off each type.

"One of those should sound familiar."

"Oh yeah, it does! The guy that told us that the sixth guy wasn't dead?"

"That's the one."

"There's a lot of others, too, aren't there?"

"A lot. One definitely deserves to be in the list, but you tell him he needs an easier name for this sort of thing. Still, this should do for now. Also, I was pretty generous, throwing you in among the great ones. You aren't there yet, you know."

"I know - although honestly I could have passed on being mentioned, for certain reasons which shall remain unsaid."

He smiled a little, and then said "Oh, and this should come in handy, with a little standard subtraction." Here he handed me a slip of paper with the numbers "1187632972091111342091605693589464874445495" written on it.

"What's this?"

"It's like one of those white things on a piano."

"Oh."

"And one more thing - probably not necessary, but just in case - you're still in school, right? Well, take a class in the 27th period. The class after that is an exclamation, you know?"

With that he walked off. What was he really trying to tell me?

It is apparent that we are talking about

some prominent Puzzling users. (They're mostly the ones near the top of the top-rep-this-quarter page.)

"Yeah. Yellow hair, red jacket, likes that one guy named Sissel."

This is clearly Deusovi.

"Hmm, what do I say? He kind of looks like a short cafeteria with a Cyanocitta cristata painted over the front."

jafe. Cyanocitta cristata is the blue jay; replace the first letter of "cafe" with a J.

"Well, he's got a diamond and a name like a politician - senator, in fact."

Clearly Rubio.

"Oh, sorry. Figured it'd be the easiest way for you to recognize him. Next one's easy though. You ever seen a flat die?"

"Now give it six sides."

Hexomino. (Flat die -> domino -> hexomino.)

"Next fellow's pretty famous - his reputation precedes him. Matter of fact, he once got an email from that Void guy."

This has to be Rand al'Thor -- see this question.

"Well, he got mistaken for a drum, once. Then he had that one time - you especially would remember - the three-piece thing."

I think this might be Tom (a tom-tom is a drum, but if you have "tom" only once then you get Tom; and one of his puzzles is titled "Three easy pieces". Brandon_J commented on it, but I'm not sure whether that's enough to justify "you especially would remember".

"Not very inquisitive, this one."

"Shy, perhaps?"

"Not exactly, although he did define that word once."

There was a question What is a Shy Word? asked by Engineer Toast and solved by M Oehm ... who hasn't posted any puzzles, which I guess is why he's "not very inquisitive".

"You, described sarcastically."

Brandon_J, of course.

"What do you catch, here in the US?"

Bass.

"A lot. One definitely deserves to be in the list, but you tell him he needs an easier name for this sort of thing.

I suspect this might be me.

He smiled a little, and then said "Oh, and this should come in handy, with a little standard subtraction." Here he handed me a slip of paper with the numbers "1187632972091111342091605693589464874445495" written on it.

The list begins with Deusovi's user ID but then diverges. It has the same number of digits as all our 9 prominent user's IDs together (43; we have two old-timers with 4-digit IDs and seven with 5 digits each). Obvious attempts to derive it from those IDs or vice versa fail -- so let's do the other "obvious" thing: glom those IDs together in order and subtract one number from the other. We get (leading zero for a reason that will become apparent):

09001215220500162126261209140727190528

Aha.

09001215220500162126261209140727190528

I _ L O V E _ P U Z Z L I N G . S E !

Here 00 is taken to mean space, and 27,28 are .,! in accordance with the cryptic business about 27, periods and exclamations.

So what he was trying to tell you was

"I love Puzzling.SE!"