I don't understand this - I haven't had antibiotics since I was a young child. What is the average case we're talking about here? Most colds I've had go away in

I don't understand this - I haven't had antibiotics since I was a young child. What is the average case we're talking about here? Most colds I've had go away in 3-5 days max. Old and vulnerable people with infections, I get, but no reason anyone under the age of 40 should be taking any unless very serious case.