Four reasons
1 - Elon musk is much more mature than most people like him, he has truly understood and practices that money is only a means to the end, not the end itself. The end is the purpose in your life, Why are you born in this world? What is your job here in this world? What are you going to leave in this world when you die? What are you going to be known as? You re not going to take any of the money you make along with you, when you die. He is not just here to make a small dent in the universe, he is attempting/working to change it upside down, for a good reason
2 - Elon Musk is not afraid of doubling down on his bets risking everything he has. The other person that I know that did this was the founder of Reliance, Dhirubhai Ambani in India in the 80s and 90s.
3 - He is a good guy, really cares about the world and its problems and putting a genuine effort to solve them at a scale only a very few people can, not just want to make his millions/billions and sail around in a yacht
4 - And also he is smart guy, he is able to question conventional wisdom in a logical way and also prove several things we thought were true as wrong for example until the Tesla car was made not many people thought electric car could be that powerful
That is definitely not easy, and not everybody can do that.
The reason is with many successful people, once they make their first $100 Million or $1 Billion they are afraid of losing it. So they don't make big bets from then on. They have their portfolio, they balance the risk in their portfolio, they invest only a tiny portion of that portfolio in a high risk project, so they do the same thing. They play it safe, they do the same thing they have done in the past. Even though their comfort zone has expanded they don't attempt something bigger than what they have done before.
Only a very few people in this world are lucky enough to even think about billions, but they all play it safe.
If you think about it, 500 years ago when Columbus set sailing to discover India it was crazy back then, not many people knew where the ocean will take him, in spite of that he set sail, attempting to go to Mars now with all the technology we have is not something that is something similar to what Columbus attempted, if at all someone can do it, it is people with those billions or the government, unfortunately the most powerful government in the whole world the US government hasn't done that yet, so that means only people with those billions have a chance in doing it. And I am glad Elon Musk is trying it, after making this much money and made so much wins for himself and his investors still has his head on his shoulders.
Here is a good video on Elon Musk
Also check out my book Puga Sankara's Supply Chain Blog - that is a must read before spending Hundreds & Thousands of $$$ on your MBA or Masters Degree to get the best ROI or before starting your Entrepreneurial journey.