Leicester City defender Liam Moore knows only too well that he needs to be a fast learner if he is to make his mark in the Premier League.
The top-flight can be a ruthless battleground. There is no place to hide, especially for young players.
You are up against the world's best, who will take great pleasure in exploiting your every weakness, not to mention that the world is watching.
Moore is still only 21 and, at Chelsea this afternoon, is set to face the toughest test of his still blossoming career, tasked with keeping tabs on £32million Diego Costa with an eye on Eden Hazard, Oscar and Cesc Fabregas floating around behind.
Moore passed his first Premier League test, though, putting in an extremely mature performance against Everton last Saturday.
Not one to shy away from a physical contest, he quickly flew into a meaty, and perfectly-timed, slide challenge on the imposing figure of Romelu Lukaku. He was not to be pushed around.
Moore went on to win all five of his aerial battles, made 12 clearances and, according to the stats, did not miss a tackle.
His last-minute block to deny Steven Naismith a simple tap-in showed a game-awareness far beyond his years.
But Moore knows he still has much to learn. "I need to be listening to the people around me because they have lots more experience than me," he said.
"I am only 21 and there is bags of experience in the dressing room. What little bits and bobs I can pick up from them, the gaffer and from Shakey (assistant boss Craig Shakespeare) are really important."
There are plenty of people around the place. His manager Nigel Pearson, for a start, knows what it takes to be successful in the heart of a Premier League defence.
There is also the man who will be lining up next to him today, Wes Morgan.
Although Morgan is also a Premier League new-boy, he has 13 years of professional football under his belt. Like Morgan, Moore is a likely candidate to wear the captain's armband in years to come.
"I suppose I have grown up a lot around Wes, since I started training with the first team," said Moore.
"He is someone I looked up to straight away for the way he plays and conducts himself.
"I will always sit down and have a little word with him. He is very complimentary and is very good with what he says and does."
Then there is Marcin Wasilewski, who has 60 caps for Poland, and Matt Upson, who has played most of his career in the Premier League.
Moore is looking forward to soaking up all he can.
