I've seen a broad mixture of those scenarios over time, people of various personality types doing it (myself included).
The one thing I'd say, is that it's critical to know whether you have a strong internal drive / self-motivation. If you don't, it can be a dangerous context to put yourself into (dangerous in the financial or time waste sense). If you don't have that internal always-on motivation, it's super important to have a firm plan and object/thing/business idea that you're going to be pursuing before you quit. Start at least drawing up some sort of minimum framework before you quit, laying out what you're going to do, how you'll spend your time, what type of lifestyle businesses you're interested in, plot everything out financially as much as possible and so on. Good advanced planning will save the day and help prevent catastrophy as the road gets challenging. It's a new type of 9 to 5 job, although it's more likely to be a 50-80 hour job getting started. Without financial pressures, you have to either naturally self-motivate strongly so you don't constantly veer off (get lazy, get distracted, get bored, and such), or follow a fairly strict plan that you've laid out for yourself ahead of time to keep yourself sane, productive and making progress.