Ok, I'll give an example from my life.
My DH loves classic cars. We go to classic car shows a couple of times a year.
8yo DS is also interested. I enjoy the day out. 10yo DD is totally disinterested.
So we choose car shows where we can have a wander around together before Dd and I go and look at something that interests her more, such as art galleries or museums.
And DH doesn't do what I saw a man a few years ago do - stand with his DS and explain the ins and outs of a engine, "Look, these are the pistons, and they do suchandsuch, this car is a 4 valve, as you can see here, but the one over there is a 6 valve which means it has 359 HP more, and has a top speed of 239 kmh, with a torque of 345 newton meters"
(yes, I know none of that makes sense, but it didn't to the poor little lad who was bored out of his mind and just wanted to look at shiny cars)
Age appropriate learning is the key here. Give them the big picture and they will later want to learn the details.