For example, for my first business blew way too much of my initial budget on advertising, because it was the aspect of running a business that I was attracted to the most. As a result the business teetered on the point of sinking and took 6 months more to get going than it should have.
So the lesson learned - dont spend too much on advertising just because you like it. Is a fairly plain and simple positive in contrast to the negative of near bankruptcy?
Does anyone have any mistakes like this? Where the lesson learned seems almost pathetic in comparison to the damage caused?