Every project have 3 pillars or attributes which sets the outcomes of the project. They are 1) Scope and/or Quality 2) Time and/or Schedule 3) Cost and/or Resource Owner of the project can only control two attributes, while the third one comes it self.It is impossible to have three of them as per desire. It is also called "Triple Constrain" in project management terms, just if in case some one want to read further about it.  

Once you have validated the idea, next step is to turn it into a business ( AKA Startup ). Here is the formula to calculate the economics A = Number of people with the same problem B = Amount that each A is going to pay C = A * B D = Cost of providing B to A If C>D, then there is a business. If not, there is not. Now C wont be greater than D at all times, but in [...]

NOW. There is no perfect product in the world. It improves over time. The longer you take to build, the lesser are the chances of it being successful. Ship the product as soon as possible. Get the early adopters, take feedback and build based on that. Do not be lost under your assumptions.    

TL:DR Instead of building something you want, ask people what they want. Long I am an Engineer my self and love building things. I have a way of thinking and I think that every one should think the way I think. This lead me to build a product that solves a problem in a specific way. Here is where the mistake happens. I can start building things under the assumption that the world thinks like me. Other option is that I start asking [...]