Where can I see all of my notes on a student?
You can find the student in the all my students view. Link to "All my Students" view.
Then you can change the number of students shown per page to include all of your students. (in some cases over 1000) Then you can search for the student by name.
After that choose the action Show all Feedback.
That will open this list of previous feedback. All of the arrows on the left side are expandable so you can see your full notes.
You can also see this list in the create new feedback window, while creating a feedback for this student. Previous Lesson Feedback & Notes are listed on the bottom left side. Here again, the arrows are all expandable to see the full text.