Young's 124 runs from 226 balls, including 15 boundaries, has put CD on the front foot, after the hosts won the toss on Tuesday and elected to bowl.
"It's been a while since I last scored a ton. There's been plenty of 50s," he said.
The Stags patiently built on the overnight total of five runs for the loss of no wickets.
The No 4 batsman arrived to the crease with CD on 71-2 to forge lucrative partnerships with No 5 Jesse Ryder (61 runs) and No 7 Dane Cleaver (47).
Opener Ben Smith is unbeaten on 24 and will soldier on with No 9 Ajaz Patel who has yet to score.
"We've still got three wickets in the bank so we can get out there to extend our lead - hopefully double it and then some - then bowl to put them under some pressure," said
Young after Matt McEwan claimed 4-71 although openers Hamish Bennett and Brent Arnel were pivotal in their frugality.
But that miserly effort wasn't why Smith only managed 24 runs. He retired hurt on 10 runs after 5.3 overs in the day.
"Smudge came off. He got hit in the nuts," he said of Smith, adding the opener was already feeling queasy before he went out to the crease.
"I don't know what it was. Maybe he had eaten something funny and then he goes out to bat ... and cops one flush in the box.
"We could even see how white he was so it took him about five minutes to get off the ground and then batted for an over or two before saying he was in too much pain and came off," a laughing Young said.
For CD, having the tail wag is imperative with Patel and Seth Rance giving as much strike as possible to Smith today.
"When Ticks [Blair Tickner] comes out he's a genuine No 11," he said, revealing the rookie seamer had the luxury of making a guilt-free knock with the bat.
A decent shower crept in yesterday after lunch but the umpires persisted.
Reflecting on his ton, Young felt "balanced" in his 334-minute occupation of the crease.
"That means I could hit the ball down the ground and work on our defence as well," he said, working out the bowler in deciding which shots to play and when to dangle the ball outside the offstump.
With cold southerlies, the ball wasn't doing much but the wicket is promising for CD to take more scalps.
Ryder, in reaching 29, chalked up a milestone 8000 runs in first-class cricket.
"Jess did very well when he come out because the seamers were hitting in very good areas," he said of his partnerships. "Dane came out late in the innings when the ball was older and played freely. He took a few balls to get going but once he did he was the Dane Cleaver of old and makes batting look easy.
Young said Ryder's knock was a fantastic milestone.
"Not too many people in domestic cricket can say they've scored 8000 runs so Jesse's stoked."