Why did he suddenly say “happy days” here?

Rebecca

"Happy days" is an expression commonly used in the UK and Ireland to express happiness or satisfaction at the current situation. Jamie Oliver is pleased with the ease of peeling garlic that he is experiencing, so he's used "happy days" to express this. Ex: I just got a promotion! Happy days. Ex: A: Let's have a toast for the newly wedded couple! Congrats on the wedding. B: Happy days.