Years back, I made the mistake of planting my Anahiem chilies next to my Jalapeños. Cross pollination!
With the years has come an increased sensitivity to hot. My wife only uses a small fraction of the Thai chilies in her cooking as she used to. A Thai recipe for steamed fish covered with chilies, garlic and lime is forever out of our ability. Used to love it.
My wife has also become sensitive to anything even mildly spicy over the years.