Lack of comprehension while working at school

Today, while I was working in a second-grade classroom, I noticed that I had trouble checking a student's writing. She had to copy her story over and I had to check it for errors. Whenever I got to a place, where she had to fix the story, I had great difficulty finding that same sentence on the new copy. I also noticed that when the teacher was teaching place value, that it was a bit confusing for me. I know that I don't usually have a problem with this. If I write this down, then I know what math page they are working on. This is confusing for me to comprehend. The fact that I can't remember what has just been said greatly impacts whether I can comprehend things.