I love this show! For Americans, I'd describe it as a blend of Jeopardy (you do need to know your stuff) and an anti-Family Feud (as you are trying to find the answer the studio audience previously knew least, not most). Contestants are rewarded most if their knowledge is deep on some subject, but one must also have broad knowledge because any one question could trip them up and eliminate them from play that day.
The presenters are perfect (I'd already loved Osman from QI, but Armstrong was new to me.) I laugh at myself for my total lack of knowledge of snooker and rugby (really not things here in the US, though I did play snooker one weekend in Canada), and I enjoy the heck out of knowing all the answers to the word and literature questions and most of the plant ones. I've been surprised at how much Brits know about American politics and how little about literature. I'm pleased at how different our favorite desserts and childhood games are. We are cousins, but we are not identical. All of that is wonderful, for it increases my knowledge of our similarities and differences, and also makes me want to bone up on my knowledge of UK politics! Turn about is, after all, fair play. I wish my streaming subscription carried more seasons, back to the beginning, but I'll hunt more down somehow on the interwebz. I'm addicted.