I started with software development back in the 1990ies not just to develop good software but especially to implement my own ideas. Now I have got the experience, the network, my friends and family who are supporting me, some potential customers and last but not least co-founders I was working with for a couple of years. So in my opinion it simply was the perfect moment for quitting the job and starting to do what I was thinking about for years.
So I had the last day at the company I was working for the last 4.5 years exactly one week ago. I didn’t knew how the last weeks would be then everyone known that I would leave the company but it turned out that most of my co workers were treating me with a lot of respect and they seem to appreciate what I was planning. Some told me that they hope to find a way to work with me (i.e. my own company) in future. Even the talk to our CEO was a nice experience because after the explanations of why I wanted to leave the company and telling him what I was planning to do we stopped talking about the past and started talking about new ideas and founding companies and he gave me some good advice.
So if you are in a similar situation my advice is to recognize the right moment but don’t wait to long. If it feels right than just do it and find your own way :).