The truth is, that the focus is currently on a very specific niche which doesn't excite me too much. Some people say that co-founding a company is kind of like

The truth is, that the focus is currently on a very specific niche which doesn't excite me too much. Some people say that co-founding a company is kind of like getting married. And other people say that marrying someone based not on what they are, but on what you imagine they might become, is the height of folly. Anyway, the problem doesn't excite you, and your co-founder's approach doesn't excite you, and your stomach has obviously figured out that this would be a mistake for you even as your brain continues to debate the issue, so it's time to discover a prior engagement and politely decline.