Anne Frank's diary was different from other autobiographies and from one she may have written later in life because her diary was never meant to be read by anyone else on Earth. She had no idea that her diary would be found after her death and published.<span />
A. The Diary of Anne Frank was never intended for publication which is why it is so riveting. She did not write this for the public and these are her most intimate thoughts. An autobiography often just recounts the speaker's life. But with Anne we are there, we are experiencing it with her raw emotions.
B. If Lysander said he regrets the time he spent with Hermia, the line would lose the sincerity and commitment Lysander hopes to portray because repent implies hope and change.