Paul Graham writes in his “Revenge of the Nerds” article:

… in the OO world you hear a good deal about “patterns”. I wonder if these patterns are not sometimes evidence of … the human compiler, at work. When I see patterns in my programs, I consider it a sign of trouble. The shape of a program should reflect only the problem it needs to solve. Any other regularity in the code is a sign, to me at least, that I’m using abstractions that aren’t powerful enough — often that I’m generating by hand the expansions of some macro that I need to write.