Direct characterization is when the author tells the audience how is the personality of the character. Dr. Shlemiel is a complex character, showing many different qualities, revealing faults as well as virtues.
Indirect characterization is when the author shows things that reveal the personality of the character. Dr. Shlemiel develops some changes and learnings that reveal some truth about life. But in the end, it is up to the reader to draw logical conclusions about the character's personality.
Well I would say do an event that is most signifigant to you. It could be a Tragic or Happy memory, or one that is simply close to your heart.