You've added two conditions not present in the original comment.

Some people may "abuse" such things, but I'd say most people legit have days when they're under the weather and feel fine the next day.

Also, if you have kids in daycare or something? A cold twice a month is pretty much the norm as I understand it. I love my nieces, but there's a 50/50 chance each time I see them I'm going to wind up with a minor cold. Toddlers are awfully efficient at spreading disease...