But as he approached 40, Fabrice Grinda, a French technology entrepreneur with an estimated net worth of $100 million, couldn’t shake the feeling that something was terribly wrong. Somehow the trappings of his success were weighing him down.

He was having a midlife crisis — in reverse.

“People turn 40 and usually buy a shiny sports car,” Mr. Grinda said during an interview in a penthouse suite at Sixty LES, a downtown boutique hotel. “They don’t say, ‘I’m downsizing my life and giving up all my possessions to focus on experiences and friendships.’ ”

But that is exactly what Mr. Grinda did. He moved out of the Bedford house in December 2012, ditched the city apartment and got rid of the McLaren. He donated clothes, sports equipment and kitchen utensils to the Church of St. Francis Xavier in Lower Manhattan. He gave his furniture to Housing Works and he packed a Tumi carry-on suitcase with 50 items, including two pairs of jeans, a bathing suit and 10 pairs of socks.

He dubbed it “the very big downgrade”: He was going to travel the world, working on the fly while staying with friends and family. He was purposely arranging things so that he would have a chance to focus on what was meaningful in life.

“When I looked back at the things that mattered the most to me,” he said, “they were experiences, friendships and family — none of which I had invested much in, partly because I was too busy, and partly because I felt anchored by my possessions.”