Teacher Kyle Schwartz wanted to get to know her third-grade students a little better. Just turning the corner on her third year of teaching at Doull Elementary in Denver, Schwartz came up with a lesson plan she thought would help her students share their thoughts.

Schwartz asked her students to write her a note that started with "I Wish My Teacher Knew ..." The third-graders could then take it from there and share anything they wanted their teacher to know about them. She had no idea just how honest her students would be — or how heartbreaking their responses would be.

"Some notes are heartbreaking like the first #iwishmyteacherknew tweet which read, 'I wish my teacher knew I don't have pencils at home to do my homework.' I care deeply about each and every one of my students, and I don't want any of them to have to suffer the consequences of living in poverty, which is my main motivation for teaching," Schwartz told ABC News.

Moved by her students' responses, Schwartz started sharing them on Twitter, using the hashtag #IWishMyTeacherKnew.

Schwartz encouraged other teachers to give the #IWishMyTeacherKnew lesson plan a try to get to know their students better and learn more about the issues they faced at home and at school.

The idea quickly caught on and tweets with the hashtag #IWishMyTeacherKnew started popping up from all over the world.

Like this one from Dawn King, a fourth-grade teacher:

And this one from a middle-school teacher of education consultant Rebecca Shoniker:

Or this gem from a student of Twitter user Cassie Norsworthy who asks for more time in recess so that his brain cells can breathe clean fresh air and not "stinky classroom smells."