He spent ten years liquidating all of his assets and caring for his aging parents until they passed on. I don't know that it explains the entire employment gap but it seems reasonable that he would be a tough sell for many companies: older, and despite the good education and prior employment history, his skills are bound to be rusty. He was deliberately not working during that period.
He was only 33 years old in 1990. According to his story, he already had 8 years of experience as a senior engineer at Lockheed, plus two masters degrees in Physics and EE, and more than a decade of computer programming experience, and connections all over the aerospace industry. If he made a choice to not work for the next 18 years, while becoming indigent and sliding into homelessness, that's not something to be solved by the American economy. And he is not the first man with ailing parents, you know.
