The perplexity is completely normal. It happens to everyone. Isn't there a way you can test-run the ideas on a small scale while still at your job? Ideas can be pretty funny sometimes — they look all beautiful and fascinating while still in our heads until you put them to test. Then you will realise those ideas aren't so fantastic after all. If you ask me, I'd say you test the ideas first on a minimal scale and see how it plays out. If it works out fine at a minimal level, you can look for possible ways of scaling it before considering ditching your job. But don't be in a rush to quit that job yet. Even if you must quit, give yourself a time frame, say 6 months to one year. This is to give you enough time to save up money from your job while still test-running your ideas and also you would have some funds to fall back just incase. As for the perplexity, it will always be there until you start executing the ideas. Execution gives clarity and confidence.