Deeper understanding
Scrutiny <- needs clarification
Change in perspective

One of the key principles behind taking smart notes is to have a focus on writing. By writing down thoughts and ideas we force ourselves to really think deeper about them and this quickly brings to light parts that are not yet fully understood. This leads automatically to a deeper understanding.
By changing our perspective when listening or reading to knowing that we're going to have to write about it we also change the way we listen or read. It forces us to pick only the interesting things that are worth writing about.