Headwinds and hills are similar but what sucks about headwinds is you don't get the satisfaction of cresting a hill. The winds picked up on my ride today and luckily I road into the wind on my way out and I had a tail wind on the way home.... a bonus. Have you ever noticed that when riding with a tailwind you feel like your in stagnant air and you tend to sweat a lot? I guess that only happens when the tail wind is blowing at the same speed your riding. Don't get me wrong, I'm not complaining about a tailwind... I'm just asking if other notice this.