The last time I made enchiladas for dinner guests, the menu included guacamole. Little did I know, my svelte neighbor from across the street was allergic to avocados—she also loved them!

Without saying a word to anyone, she heaped guacamole on her plate. Bite after bite, the green cream disappeared.

Suddenly, my neighbor stood. “Excuse me,” she said. “I need to run home for a minute.” And out the door, she raced.

Conversation around the table resumed as if nothing unusual happened.

About fifteen minutes later, my neighbor returned. The sleek, body-forming tank top and slacks she wore earlier in the evening were replaced with a voluminous and billowing Hawaiian muumuu.

Her narrow, heart-shaped face was now full-moon round. Her slender fingers looked like puffy sausages.

Seating herself at the table again, she heaped guacamole on her plate. “I love this stuff, but avocados always make me swell up like a watermelon.”