It is an interesting fact that Alexander Fleming discovered penicillin by accident, and that Isaac Newton discovered gravity as a result of an apple falling from a tree and hitting him. In the same way – though admittedly on a smaller scale – some brewing mistakes and happy accidents can lead to a different and unique taste in a brew that makes for a worthwhile addition to your rotation. Admittedly, more accidents go wrong than right, but it is worth noting that the process can work in your favor even when mistakes are made.
This kind of happy accident can have the most unexpected results. If you add too much of something, too little of something else, add something at the wrong time or leave too much or too little time for something to happen, all of this can change the taste of the finished product quite markedly. As a result you can end up with something that you are happy to drink for the rest of your time as a home brewer. For this reason as well as many others, it is a good idea to keep a notebook detailing what you do during the brewing process.
Of course, people are slow to admit to mistakes, especially when the results are such that the mistake turns out to be a winning move. So we will never know how many of the beers out there on the market were the result of clever research and sound practice, and how many resulted from one person’s slip up. And maybe that would destroy the magic.