Why did I choose the London System?

That's a good question.  Why did I choose the London System?  Simple. It's because I heard that my opponent favored this opening.  Now, you might be asking, "Why would you want to play an opening that your opponent is very familiar with?"

That's a fair question.  Here's the simple answer.  It's because it makes me a better chess player. If I'm unfamiliar with an opening, there really is no better way for me to learn it than by playing it against my opponent in a rated game.  

I figured that if I played white, I would play the opening to the best of my ability and see how my opponent played against it.  If I played black, then I would be able to see first hand how he or she played the London System.
 

In the following game, I was white against this particular opponent. Whether or not this was his favorite opening was never really established.  It was simply hearsay.  But what actually happened in the game was that I was never really able to play it because of one particular move that he made.  Consequently, I was forced to play the Colle System:  the opening I usually play. Though I was able to develop in a fashion similar to both the London System and the Colle System.  

The result was one of my most hard earned and satisfying victories over a very worthy opponent rated approximately 200 points higher than me.

In summary, I had an idea of the opening my opponent tends to play. Rather than avoid the opening, I figured I could learn something from deliberately playing it.  One thing is certain.  My opponent was familiar with the opening, so an endgame was likely to happen and did happen. Just one more reason out of many reasons to support the idea that studying the endgame is vital.