Even Mick Schumacher's closest racing friends know nothing about the condition of the 19-year-old F3 champion's famous father.
The entire world is in the dark about the physical condition of F1 legend Michael Schumacher, following his late 2013 skiing accident and brain injuries.
One of Mick's closest racing friends, Nicklas Nielsen, praised the talent and personality of the young German driver.
"I know him very well, also privately," he told the Danish newspaper BT.
"He is a very quiet and calm guy. Very nice and welcoming and he talks to everyone.
"He is nothing like Max Verstappen, who cares about nothing and nobody and just wants to win. Mick has been brought up properly," Nielsen added.
He said he also knew seven time world champion Michael before the accident, calling him and Mick "simply nice people".
But since Schumacher's accident, nothing has ever been spoken about the ultimate fate of the now 49-year-old former Ferrari and Mercedes driver.
"It was completely closed and not talked about," said Nielsen. "I still do a little karting with Ralf Schumacher and his team and nobody talks about it.
"It may be that Michael is on his way back and will only come out again when he is completely rehabilitated. But it's hard to say what's going on," he added.
"Mick does not say he is sad about his father, he just said sometimes that it is sometimes hard," the Danish driver said.