I'm the kind of person who finds himself reading about a new technology or a cool algorithm, and tries to implement it based on the high-level description. Unfortunately, I don't always guess everything correctly, and sometimes the implementation turns out to not work; or it kind of works, but not as well as expected, which can be even worse.

A key example of this for me was when I read about Evolutionary Algorithms. At the core, it's sounds so ingeniously simple:

Create a population of individuals
Score the individuals based on some performance metric
Kill off the weakest performers
Create children from the surviving parents
If not finished, go to #2

Tom Mitchell's CMU project, including NELL