Since I don't come from a privileged background, I couldn't afford to be irresponsible with career decisions. I wrote two books alongside my job and resigned only when I realised I can make a living.
I'm one of those lucky guys making a living out of something I really enjoy doing. That's a blessing. But you never know. What if my subsequent book series flops? I don't come from a wealthy background, so I'd be left with no choice. I'd have to go back into banking!
I think it's a fallacy to say that a good book sells itself. It doesn't happen. I'm a voracious reader and I can give you a long list of books which should have been best sellers but they aren't. How can you buy a book if you haven't heard of it?