I will take the flu over a standard cold any day. 18 hours is actually pretty good, mine is usually a day or two, but I rather suffer and be in pain for a day or two, than to have an annoying cold that drags on for months. Flu hits hard but goes away fast, while colds just drag on and on. If there was a vaccine for the common cold, I'd actually bother to go take it. Thankfully I don't really get sick that often though. Maybe every 2-3 years if that. The last time was several years ago when I got strep and it turned into a nasty cold.