1. The document discusses reasons why people listen, such as to gain information, create relationships, and broaden horizons, but notes that listening is a neglected skill and the average listener retains only half of what is said after 10 minutes and only 10% after 48 hours.
2. Some reasons why people don't listen well include selective listening, talking faster than thinking speed which can lead to daydreaming, and lack of interest if a topic is boring or doesn't concern the listener directly.
3. Additional factors that can interfere with listening include preconceptions about the speaker based on attributes like hierarchy, education, or gender, as well as physical and mental distractions.