We were poor growing up - my granny never really wanted to leave her home town but my grandad had serious wanderlust after he was in the royal marines in WW2. He ended up working in Africa for a while and would have loved to stay. Also my parents backpacked first around Europe and then India and the far East when they were late teens/early twenties - my mum was a trained nurse so she worked wherever she could to earn money for their travels - six months in Beirut (my dad's art degree was less useful!). I was left at home with the grandparents. I first went abroad aged 11 on a day trip to France and then aged 12 to Spain: we had very little money and my parents and I were stuck together in a tiny tent. Some days they went without food until dinner... Which sounds mad but they loved traveling.
Their love of travel rubbed off - now I'm obsessed, we even lived abroad for two years. I would have continued living in different countries but my husband found it too stressful. My kids loved it too - interestingly both want to live abroad when older.
I value holidays so highly that I'm happy to give up all sorts just to make sure we go somewhere different every year. I can't wait until I'm retired and can spend months travelling Europe in a campervan. i have lists of countries I want to visit and worry that I'll never get to them all. One of the best things about working in the Middle East was the sheer diversity of the people I worked with: Lebanese, Eqyptian, Iranian, Iraqi, Armenian, Emirati, South African, Indian, Pakistani, Filipino, French, Tunisian, Moroccan, Algerian, Palestinian, Jordanian, Serbian, Russian... I couldn't get enough of their lives, their cultures, customs and FOOD. Someone would get a new car and bring in food to celebrate, or it could be a birthday or a special day and there'd be food. Oh man! My kids' school held an international day with stalls of food, clothes and culture from all the countries where their pupils came from and there were 47 different countries represented (with the Indian one the best as they played music and had dancing. However Finland was moomin themed though so...).
I honestly don't know anyone who hasn't been abroad - I completely understand if money is an issue. But travel doesn't have to be stressful airports and packed resorts. You can get across to France so cheaply and in 7 hours drive be at some of the best beaches on the planet. There's a whole amazing world out there. And it's better in real life than in pictures.
Sorry for the long post but I just wanted you to have a taste of why going abroad is so magical for some people. It's what keeps me sane working in a very stressful job with a hideous commute (the job thankfully also means some travel). It is the highlight of my year. I wish I could travel all year round.