What did I learn from each drawing exercise?

Self-portrait- The hardest thing I found about doing a self portrait was capturing the life like details of a persons face. I think I did well with my hair in my self portrait because it was the simplest to draw while still being detailed. This exercise was helpful in making me think about drawing what I see not what I think.
Person from memory- I think this one was the hardest because I didn't have a reference to draw from. I am impressed with my basketball hoop though i though it was pretty good. What was helpful about this exercise was me was being able to recall someone a certain way in my mind. I though this was the hardest drawing we have had to do so far.
My hand- The hardest thing about drawing my had was proportions because we couldn't trace them. I think I did do well with the width of my fingers though. This was very cool though and I though it was helpful because again it made me think about shapes and sizes without focusing on what it really was.
Upside-down picture of Igor Stravinsky- This whole drawing was really hard cause it was obviously upside-down and very detailed. I think what made it easier for me was the fact that I had had to draw upside-down before so it wasn't totally new to me. Over all this drawing I would have to say that this was my worst drawing out of the set of drawings even though I had drawn upside-down before.