When you thought you were right, but you were completely wrong, what was it you were wrong about?
Most people have an idea and are convinced it might actually work out well. Often that's not the case and they are completely wrong. I'm just curious, what was the detail you were missing in your predictions?
As for me: I created a webapplication and assumed people would be happy using a certain feature but apparently they didn't :-). Most signed up and never came back again.
If you are interested in discussing ways to improve your 'customer-need-searching-skills', let me know.
Cheers
My mistake was googling general industry numbers as an indicator of possible market size, and then assuming the market was captive and that each potential customer were the type willing to convert.
You need ask questions to the users, on a broad scope, you might think you have huge market because the market is big. But in actuality the niche that is interested is smaller. It doesn't mean your business is useless, you just need to reassess.
Ask first, build later.