Every successful company I can think of started out doing something that bares only a passing resemblance to what they eventually became successful with.
Twitter began life as Odeo, a podcasting platform. Airbnb was originally conceived as a solution for conference attendees. PayPal started as a way to beam money between handheld personal organizers.
Netflix, for example, started out as a video-rental-by-mail (with due dates and late fees) before eventually morphing into a subscription service, and then (9 years after launch) to a streaming company.
None of these companies could have gotten to where they are – which they did by twisting and turning their way to eventual success – if they had never taken that first step and collided their initial idea with reality and got testing.
Ideas, Fear, Idea Validation, Failure, and then if you’re persistent and a little lucky, Success.