I didn't travel "abroad" until I was in my 30s. I grew up in the Toronto area, and other than trips down to New York state and over to Montreal, hadn't been anywhere until I was into my mid-20s. I'd taken a few business trips to the USA and a few places in Canada when I decided to spend a week with friends down in Cancun, Mexico when I was 31. Even then, I wasn't impressed, and put off more international travel to the undetermined future.

It was really my trip to Cuba, and specifically Havana when I was 32 when I caught the bug to travel. The mix of the way the city was architectural and the people I met there really made me want to see more. I started travelling after that, nervously at least but eventually building more and more confidence.

Part of what kept me from travelling internationally is fear of the unknown. The world was a scary place, and being at home was always safer than being away.

Perhaps your wife is like me, and will warm to international travel after getting a taste. As others have suggested, a "safe" destination like the UK or Europe might be just the appetiser she needs.

Enjoy your travels!
Greg