I love analogies -- I really do. I probably rely on them far too much to convey and even analyze concepts. Everyone knows the old adage that all analogies limp -- they are always imperfect representations. Often these imperfections are themselves revealing, but sometimes they are downright misleading.
Here's one you hear all the time in some form or another: 'Entrepreneurship is like a roller-coaster'. Superficially, sure I get the point.... emotional highs and lows; ups and downs; twists and turns. But the truth is that entrepreneurship is NOTHING like a roller-coaster. In terms of the emotional volatility that the analogy is meant to convey, the sometimes used comparison of entrepreneurship to a passionate romantic relationship is better.