If you are one of those few people who actually love what they do, then you are a lucky fellow indeed. However, you can only state that you are successful if you also have a private life. Because let me be honest: those people who work 24/7 have no real life. You might be doing what you like all day, but what or who are you doing it for. If you have no time to spend your money or share your joys and regrets with, then you do not really live.
Your body and your brain needs time to relax, and it will even help you with your job, as well. When you are doing an activity that is different from your daily routine, then you are physically and mentally recharged so much that you will have more energy to your usual tasks, as well. You will be more creative, more motivated and more able to perform your tasks if you deliberately avoid work overload.
You need to learn to set boundaries for yourself. Even if you feel that you would be ready to work even on Christmas Eve, you should spend time with the ones who you love, as well. If you cannot resist, then finish your project later, but always spend some quality time with your hobbies and your friends or family, since you might wake up one day, wishing to turn back time, but you will not get it back. Find the balance and strive for better in your private life, as well as your professional life.