I consider myself well travelled and I've made it to 31 of the cities on your list. I've also been to 49 different countries but still plan to add a number more to this list! I'm 36, so still fairly young so have plenty of time to explore new places. I think living in the UK and not having children has helped a lot, plus I took a year out and went travelling in my 20's which included 6 months in South America. Excellent continent by the way.
Even with all the travelling I still have lots of places I want to go. I planned a trip to Yellowstone and South West Canada that was delayed due to Covid. Alaska is high on my list. Japan, New Zealand, Norway, even Antarctica. I also really wanted to go to Easter Island and Galapagos when I was in South America but couldn't afford it so they're also on a future list. Far too much of the World to see!
Funny you should mention Cambridge Steve. I live about 15 miles north of Cambridge (in Ely, small cathedral city) so spend a lot of time there. Pretty city with lots to do and years of history, plus a surprising amount of greenery. Lots of cool bars and restaurants too. Ely is well worth a day trip too and only takes about 10 minutes to get there on the train from Cambridge.