Nassim Nicholas Taleb on how we tend to reduce knowledge by narrating it:
"Both the artistic and scientific enterprises are the product of our need to reduce dimensions and inflict order on things. Think of the world around you, laden with trillions of details. Try to describe it and you will find yourself tempted to weave a thread into what you are saying. Narratives spare us from complexity of the world and shield us from its randomness. Myths impart order into disorder of human perception and the perceived chaos of human experience. "
Now this applies to all of us, but some can handle the unknown better than others. And... There is a test to measure the ability to survive in uncertainty. Cognitive closure test would help you to identify your relationship with uncertainty.
Would you like to try the test?
When is right time to start?
You had a bright moment and formed an idea how to solve someone's problem or improve existing solution.
But you don't know where to start?
Sell your idea first to early adopter, then - build.
Answer is - start now without overthinking. Things will find theyr place after first few interactions with early adopters.
Don't build until you haven't sold to someone.
You can be your first buyer as well if solution you came with is of your personal need.