Neither do we.
But we decided 19 yrs ago when it was iffy if I would make it out of the hospital to do and see as many places/things while we could. A few years ago I was filling out visa paperwork and we had visited 35 countries at that point. Saw the Taj, Indias Dharavi slums, game drive, Cuba, Carnival in Rio, Christ the Redeemer, slums of Peru, Russia, lots and lots of other amazing places. No regrets, no if only we had for us.
Do what you won’t regret.