15) I sometimes tell a joke to tackle the issue
16) that is, about people’s ability to judge “frivolity”
17) namely, imagine Charles Darwin 150 years ago
18) at the time he disappointed his father by neglecting medical training
19) and asked, instead, to go on a two-year vacation in the tropics
20) with an emphasis on bird watching (finches)
21) the father was not impressed and thought the son was wasting his time
This is Dr. Redelmeier responding to a criticism that some of his work could be frivolous, from the NYT article on him. Apparently, he sends email in the above fashion (bulleted points) – to focus on the content of a message rather than get distracted by grammar, punctuation and syntax.