I played in dirt, ate grass, spent every afternoon in the backyard, and started eating chili's at 14 yet I developed an allergy to chili late in life.
So yeah , nah, Churchill may be incorrect
You can develop an allergy to food that you have always been able to eat before(it is garlic for me)I am also allergic to pennicillin since i turned 62 and i ended up in hospital because of it(rash and dangerously low blood pressure).I would never downplay peoples allergies as they can be life threatening and have seen a kid at school have convulsions after a wasp sting when i was about 7