Personally, I don’t recommend this. There are some people who can do it immediately due to having sufficient savings for a year. But, most people are not ready to quit one’s job to pursue passion.
So, when does this advice become applicable? If you’re really passionate about your passion, it’s going to be much better if you gradually do it. In the morning, try working and do the side hustle for some other time. I have heard of various success stories which started with this setup.
It requires a little sacrifice. Perhaps, no social life in three years. But hey, it will be all worth it.