If you thought 1st grade – Year 2 in the UK – was only about learning to read and basic maths, think again.

US primary teacher Bret Turner sometimes likes to sharpen his pupils minds with an occasional riddle, but on a recent occasion it was him who got schooled by his students.

"I am the beginning of the end, the end of every place. I am the beginning of eternity, the end of time and space. What am I?"

Things didn't go quite as he had planned.

"The first guess from one of my 1st graders was "death" and such an awed, somber, reflective hush fell over the class that I didn't want to tell them that actually the answer is the letter e, which just seemed so banal in the moment," Turner tweeted, recounting the event.

Sure, a 6 year-old giving such an answer might be slightly unexpected. But wait, there's more: "Before I finally revealed the "correct" answer to the riddle, to a largely unimpressed audience, I fielded other guesses that continued along a similarly existential vein. There was "NOT everything," "all stuff," "the end," and maybe my favorite, "nothingthing."

Yup, these kids are going places. Twitter was seriously impressed at the level of maturity of the answers, and got some food for thoughts.

Some had great hopes for the student, and hoped his grades would reflect his "e"fforts.

But others mostly thought this kid needed to relax and "lighten up", which paved the way to a very on point Simpsons reference.

The tweet, which gathered almost 82 thousand retweets and 241 thousand shares at time of writing, also spawned a debate of whether "death" was the right answer to the riddle after all.

The thread offered some very interesting view on the importance of the letter "E" and its meaning from language to language. Like one of its meaning in Ancient Hebrew (the letter was used for a variety of words, including "window" and "fence") , as explained in this tweet:

Some also came to "E"'s rescue, arguing the answer "the letter E" was interesting in itself and as wasn't "banal" as Turner seemed to think.

Some went very far, but Turner didn't seem to mind:

And other offered their suggestions for the kids' next homework.

Turner seemed surprised of the attention his thread gathered, but pleased with the results. Although he expect his students to be a bit blasé about the whole thing. "I'm considering telling the kids tomorrow that a tweet about them went viral, and given their facility with the internets, I expect their response will be "sure but did it go SUPERviral" and "just how many retweets are we talking about here" and "can I go to the bathroom," he tweeted.