In Bob's life he is surrounded by sycophants waiting for handouts, never wanting to be seen to annoy Bob nor lose his favour. Bob does not know who to trust. He has had those that he considered real friends and deeply trustworthy turn out to be thiefs and liars. A former school friend was secretly living in one of Bob's holiday homes _for years_, successfully evading detection by Bob by using his friendship to know where and when Bob will be. He was using his ties to Bob (and Bob's success) to gain favour in his own business and was using some of this money to bribe Bob's staff into silence. Apparently the friend went full "villain in disguise reveals his secret vendetta" when Bob asked if the friend needs help. Bob was heartbroken.
Maids, servers, and other staff are stealing things all the time - Bob maintains and reviews an inventory of stolen property with his security detail, with monthly targets... theft of his belongings is an ever present cost to Bob. e Bob's own family live an excessively sheltered life. His young children's best friends are their personal body guards - former military personnel that must be present around the clock as a stipulation of their kidknap/ransom insurance. This isn't a perceived threat, either. Bob's eldest son was abducted on at least one occassion, by a policeman no less.
Bob's life is managed for him. His staff manage his diet, his wardrobe(s), his social diary, of course his work engagenments take him all over the world often with little notice. He is never entirely certain where he will be and when. He is a slave to his diaries.
Bob spends the majority of his birthdays alone, on the phone to my family member, often crying about how lonely he is.
All that for money seems like a lot to sacrifice. There's also a fascinating effect that happens when the cost of things are literally of no consequence. Sentimentality is the only measure of value and material objects are just.. nothing but utilities.
Anyway, I would safely assume being a billionaire is not all doom and gloom, but it certainly has a different set of life-problems.