We all notice differences in the atmosphere when we travel: The people are different; the architecture is different; the air itself is different.
The city of San Diego is only about 20 minutes away from the border of Tijuana, Mexico. At night you could see the city lights of Mexico shining from atop the hill where my parents live in South Park. It's amazing what a difference 20 minutes can make...the sky just steps into the Mexican side was filled with smog as if there was an invisible border that extended all the way up into the atmosphere.
This past weekend, we attended a family wedding in Lubec, Maine (where some of my family lives) and we crossed the Canadian border which was only about 10 minutes away. Walking down to the shoreline in New Brunswick it struck me how clean the air was. There was a hint of pine wafting from the trees; the smell was so subtle and fresh it felt like breathing in peppermint.
While the temperature was hot, the air was as crisp as a cool fall day in New England. The smooth stones and the pier pillars were outlined with a kind of natural sharpness that seemed to me like I was looking through a lens that just got put more into focus. It was so clear I swear I could see everything better. Maybe I don't need glasses, I just need to move to Canada.