It's easy for some to give away money if they have it, but it's hard to accumulate that much money if you're one of those people.

Newmark maybe representing the occasional exception, most people who accumulate great wealth through their effort and ideas are afflicted with an addiction problem and have a hard time saying "this is enough for me". They become attached to how much more wealth they might be able to gather and recognize how the wealth they already hold plays a role in making the most of that.

Even if they somehow imagine themselves as philanthropists or minimalists, they tend to put off giving away too much too soon under the rationale that they'll be able to eventually share more if they hold out and use it more practically.

And if you don't have that kind of mindset, you're probably just not going to climb your way into the level of riches we're discussing here. You might still do quite well as far as most people are concerned, but that billionaire milestone is hard to catch without some propensity for wealth addiction.