Following your dreams means doing what you want to do, and not caring about what anybody else thinks. Sometimes that means that you have to make sacrifices. As long as you are willing to make those sacrifices when they are needed, you'll be happy with what you have around you the rest of the time.
It can seem like a big risk to abandon your usual routine for something out of the ordinary that you've always been dreaming about accomplishing. However, this is a risk that should definitely be taken. Variety is the spice of life, and new and exciting experiences are the best spice of all.
Yes, one should follow one's dream if the person would regret it if he or she does not. Sometimes, when pursuing a dream, you have to leave somethings behind. A person should be willing to leave some things behind and take a chance to do what he or she really wants to do.
No, I think a person can follow his or her dreams without immediately leaving it all behind. An individual should definitely follow dreams, but abandoning everything to do so can lead to financial ruin. Approach your dreams steadily but wisely. Keep your source of income, or at least some of it, until you start to make real progress on your dreams.