I found your comment on ethnicity interesting. It makes sense, as there's really no natural supply of tropical fruit in Northern Europe.
Conversely, I'm full blooded Mediterranean stock (Sicilian) and find that I tolerate tropical fruit quite well. I'm not sure as to what extent melons grow in the Mediterranean, but I'm certain that fruit is much more plentiful than in colder northern climates. The only melon that bothers me (lethargic, upset stomach) is honey dew. Cantaloupe and watermelon are my favorites and I feel great after eating them.
Could just be a coincidence, but there could be something to it.
There are dreams we’re taught are normal, whether it’s money or success or any of those things, but we shouldn’t believe in those things if they are not important to us. There is an ocean between our real lives and what is expected of us.” -Tim Lambesis