I've seen many countries, a few during a trip right after high school graduation. Man, I saved so much money from 16 to 18, and then I bought an around-the-world plane ticket. It was fabulous, and challenging, and scary, and amazing. I spent six months away from my hometown -- four in other countries, and two and in another state.
In Malaysia, I learned how to scuba dive. There's an island named Perhentian Kecil. It's near the border with Thailand. I spent a few weeks on it one July. On the boat en route to the island, I looked down in the water and could see the bottom of the ocean. I met people from all over the world, shared meals and lodging with people I'd just met, watched the moon rise over an expansive sea. There was a walking path between the two sides of the island, and I walked it alone many times, coconut trees overhead. Huge monitor lizards walked freely.
I'd like to travel again one day and meet people from all over the world.