Comment by blizkreeg

IMHO, and I'm just about starting on this journey myself, there is one way to test the importance or 'bigness' of the idea and whether you should commit to spending time working on it - does the problem affect a large swath of people (at least a 1M+ people?) and are the incumbent players missing out on an angle/aspect of it that you think you can do (significantly) better? The rest is your execution.