As the sun sets over Manhattan, Stefanos Tsitsipas is sitting in the front passenger seat of a US Open tournament car, looking towards one of the most famous skylines in the world and explaining his profound outlook on life.

“We are the creators of our kids’ future,” he says. “Whatever we do today is going to affect tomorrow, whether it is starting a company or putting cars out in space.”

These are not lines that you would expect to hear from a 20-year-old tennis player — he ceased to be a teenager 15 days ago — but Tsitsipas is something of a Greek philosopher. Wise beyond his years, he offers deep and fascinating conversation to stir the mind during our 30-minute journey from Flushing Meadows