You might not think so, but I believe at some point in every persons life we obtain a nemesis. Now, you might disagree with me on this, but that's because a nemesis isn't always a noticeable one, or even a long term one. You might be one of those who obtains random, short term nemesis' that many times go overlooked.
I'm not really sure which one I'd prefer... Long term you get to know your nemesis better, however, short term offers the benefit of them not sticking around long.
What say you?