|Scottish Cup semi-final: Inverness CT v Celtic|
|Venue: Hampden Park, Glasgow Date: Sunday, 19 April Kick-off: 12:15 BST|
|Coverage: Live commentary on BBC Radio Scotland. Live text & radio coverage on the BBC Sport website|
Manager Ronny Deila credits camaraderie with an important role as Celtic laugh together in pursuit of treble success.
On course for a fourth successive title and with the League Cup already secured, a Scottish Cup semi-final with Inverness CT is up next on Sunday.
"One of the most important things needed to get better is to laugh a lot and enjoy life," said Deila.
"There has been a very good atmosphere here for a long, long time and it is getting better and better."
Deila is determined to land a domestic clean sweep in his first season in charge, which would emulate Martin O'Neill's achievement in 2001.
And he stressed that there is a time and place for jokes and high spirits.
"People loosen up more when we know each other better and we are having a lot of fun here," the Norwegian added.
"But we know the moments to be very dedicated and to be focused when we train."
Deila will be without suspended striker Anthony Stokes and cup-tied midfield duo Stuart Armstrong and Gary Mackay-Steven at Hampden.
And he is expecting a tough game following last Saturday's scrappy 1-1 league draw in the Highlands.
"Inverness are a good team," he added. "They are well organised and they have a good spirit.
"Both teams want to play football so I think it will be a better match to watch than it was last time because I don't think there were more than four chances in 90 minutes.
"Hopefully there will be some more passing, better passing and more chances."
Leigh Griffiths scored an early goal against Caley Thistle but was left on the bench against Kilmarnock at Celtic Park in midweek, only to come on and net a second-half hat-trick.
Deila praised the striker for his improvement this season but insists no one at the club can afford to relax in the search of silverware.
"I see a lot of potential in all of the players but the difference between a good and not so good player is how good they are at learning and taking in new knowledge," he said.
"Leigh wanted to make a change and he has got his reward. I think you can see a lot of players have done the same.
"Virgil van Dijk is taking steps and Jason Denayer, Emilio Izaguirre is getting better. A lot of the players are into understanding and learning.
"What you did last night is not good enough tomorrow. You have to always be alert and learn new things and learn from experiences.
"And if you are in that way of thinking, you will always be ahead of your opponent."