This as-told-to essay is based on a conversation with Rob Mallernee, 50, who is the CEO of a wealth management software company. He is based in North Carolina. Business Insider has verified his employment. This piece has been edited for length and clarity. A single brilliant decision might create wealth. But the best way to keep your wealth for 100 years is not one brilliant decision, but hundreds of good decisions over many years. After more than 30 years working with ultra-high-net-worth