Seeing a program running slower and slower over time is always a shock for a programmer. Maybe I’m too eccentric, but I think an algorithm that grows quadratically as its input size increases is some form of art.
It’s a scary monster that plays with time, something which challenges your knowledge and reminds you the good old visual scheme of the quicksort. A man much wiser than me once said:
We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil.
Donald Knuth