It is not about saving money consistently. Sure, save money towards acquiring some income producing assets such as property. Passive income is key, so the money keeps coming in whether you're working or not. For example, the rental income, and other income sources from my investment properties keeps rolling in, whether I am writing, editing and publishing or not. It's liberating. Saving money did set the wheels in motion, however it is about negotiating and acquiring the right assets. Work in a career you're passionate in, and that is a bonus.
When is enough - enough. You just need to look at the 2008 GFC to know that savings don't really have that much "credit" for the future. If you find the right job then working should not be too much of a chore.
A few years ago I thought a million was enough, but I have since re-thought that. To live and travel comfortably and to provide for my son I would need about $5 million. Most of that would get invested to keep generating income for the future. Although I doubt that I will ever retire ... I am not very good at doing nothing.