Lando Norris has revealed that he wasn't even permitted to tell his own mother that he'd been handed a seat at McLaren for 2019.
"I wasn't really allowed to tell anyone. It was a bit weird," he said in a Q&A video for the team.
"I wasn't even really allowed to tell my mum, because at the time she didn't know. But my dad knew, my manager knew and my trainer knew. It was just us really.
"I had to go and say goodbye to all the F2 guys which was a bit awkward," he added. "It wasn't awkward, but you want to say something because it's awesome news obviously. But I wasn't allowed to.
"But until the announcement [on Monday] I had to keep it all under wraps."
The 18-year-old admitted that the news took some getting used to now that it had been made public.
"I don't think it will until next year, probably. It feels really early to say I'm racing next year with McLaren.
"The feeling is probably going to get worse - not worse in term of I don't feel good about it - but the sinking feeling probably isn't going to go away until I'm on the grid for the first time and the pressure is on.
"Being called a McLaren F1 driver is probably going to take a few weeks for it to all sink in. But in terms of actually feeling like a Formula 1 driver, I dont' think it will sink in for a long time."
Earlier, Norris said that he didn't think he would have got the F1 seat if it weren't for winning the McLaren Autosport BRDC Award in 2016.
“It’s helped me get to where I am now with McLaren,” Norris said. “It put me in the loop a lot more of everyone at McLaren, and given me an opportunity to get on the junior programme.
“It wasn’t just ‘he comes in once every two months’. I was coming in two, maybe three times a month, driving on the sim, training," he added. "I probably wouldn’t be in this situation now without it."
Clinching the McLaren Autosport BRDC Award puts Norris in illustrious company. Previous winners to make it into Formula 1 are David Coulthard, Jenson Button, Anthony Davidson and Paul di Resta.
“The news that Lando Norris will drive for McLaren next year is the best I’ve had in a very long time,” said Derick Warwick, chairman of the Award judging panel.
“Lando is a very gifted driver. He’s a very deep thinker and very quickly comes up with the right answer," he added. "He’s personable, humble and fun to be around."