Irish eyes on World Cup after storming to Six Nations Slam

He believes Ireland's success wouldn't have been possible without Schmidt's obsessive attention to detail.

"He keeps you on your toes," said Sexton.

"He, eh, how do I put this nicely? At times during the week you are driven demented with him but you know he is doing it for a reason - putting pressure on you in training, at meetings to make sure every box is ticked, to make sure all the prep is done."

However, Sexton - whose partnership with scrumhalf Conor Murray pulled the strings that allowed the likes of Jacob Stockdale to set a new Six Nations try-scoring record of seven - said winning a Grand Slam makes such intensity worthwhile.

"Celebrating with the lads, those are the moments that you treasure most," said Sexton.

"The moments that make the bad times worthwhile and all the sacrifices worthwhile."

Sexton, like Schmidt, was delighted with how the young seamlessly blended with the old, and praised fullback Rob Kearney for his extraordinary record in starting every game in the two championships (2014 and '15) and the Grand Slam won under the Kiwi - and also the 2009 Grand Slam.

However, Sexton warned youngsters like James Ryan, Dan Leavy and Stockdale to keep their feet on the ground.

Stockdale, basking in both his personal achievement and the warm glow of the Grand Slam is already setting his sights on greater glory.

"We've won a Grand Slam, and that's the first stepping stone to being a dominant team in world rugby," said the 21-year-old, whose seven tries put him behind only England's Cyril Lowe and Scotland's Ian Smith, who both scored eight tries in the old Five Nations tournament (before Italy joined).

"Look, Joe hasn't said 'New Zealand is the target' but your ambition is to be the best team in the world and to do that you have to beat the best team in the world.

"At the minute, that's New Zealand."

Agence France-presse