I enjoyed the first couple of Mission Impossible movies and then they were just all kind of the same. I think I stopped after #4. Same thing with the Jason Bourne movies, although actually I think I stopped after #2. I liked them, but after a couple, I'd seen enough.
I can also understand people, and especially kids, not getting into Bond. It suffers from the same problem, and if you're watching chronologically, it also suffers from being quite dated in its oldest incarnations.
For me, I watched all but the very oldest Bond movies live in real time, rather than as some vintage movie marathon. One of the things I like best about them is that each few movies, each generation of Bond, kind of acts like a cinematic time capsule. The clothes, the cars, the sets, the scenery, the acting, the direction-- all capture their specific moments in time in what I consider to be an interesting way, but all tied together by the over-arching character that is James Bond 007.
And I think being a Cold War kid also helps with the appreciation of the earliest installments of the series.