Haskell was 15 years old at the POPL’03 meeting, when I presented this talk: it was born at a meeting at the 1987 conference on Functional Programming and Computer Architecture (FPCA’87).

In this talk, which is very much a personal view, I take a look back at the language, and try to tease out what we have learned from the experience of designing and implementing it. The main areas I discuss are: syntax (briefly), laziness (the hair shirt of the title), type classes, and sexy types.

On the way, I try to identify a few open questions that I think merit further study.