Oh! That's the Haskell motto:
https://www.google.com/search?q=haskell+%22avoid+success+at+.... I'd never troll so hard as to make something like that up, only just enough to quote it. I love it as a perfectly-cut gem of self-deprecating humor.
It has had different interpretations over the years. Simon Peyton Jones described its origins here: https://books.google.com/books?id=2kMIqdfyT8kC&pg=PA283&lpg=.... But that interview was already several years after the fact. See also https://web.archive.org/web/20150419060144/http://www.comput...:
When you become too well known, or too widely used and too successful [...] suddenly you can’t change anything anymore.
The fact that Haskell has up to now been used for just university types has been ideal [...] Now, however, they're starting to complain if their libraries don’t work, which means that we’re beginning to get caught in the trap of being too successful.
What I’m really trying to say is that the fact Haskell hasn’t become a real mainstream programming language, used by millions of developers, has allowed us to become much more nimble, and from a research point of view, that’s great. We have lots of users so we get lots of experience from them. What you want is to have a lot of users but not too many from a research point of view – hence the avoid success at all costs.
Does anyone have the original slide where he used this line? It would be interesting to see what contextual clues were there at the time.
Later it turned out to be a syntactic pun: https://twitter.com/simonmar/status/246335257677271040. The official interpretation seems to be "Don't make success your top priority, because success may compromise things you care about more", whereas the hilarious version would be "Whatever you do, make sure you don't succeed."
Haskell connoisseurs can add info. That is literally all I know about it, or more, since I just Googled half of it. I do recall reading those interviews at the time, no doubt via HN.