My Most Curious Amnesia

Years ago, I found that many times, when going shopping,
I’d clean forget to purchase a tomato type of topping.
It could be ketchup, salsa, or a marinara sauce.
I don’t know why I suffered such specific mem’ry loss.
I would remember mustard, mayo, relish, and the rest.
I even bought tomatoes, as you might well not have guessed,
And complex foods like pizza with tomato stuff within.
I’ve gotten better now, but how’d the silly thing begin?