a couple of years ago, I was really serious about my winter training. I went out for 25 miles into a raging headwind. I didn't have enough food, and my route didn't take me past any food. It was cold, and I was bonking so bad that I was considering the call of shame. The tailwind I had was glorious, so I just toughed it out. The last hill before my house is usually a bit of a push, but on this ride I could actually coast up it.
I always thought that the sign of a long ride is if you only get sunburnt on one side of your body, but going out into a headwind and then coming back into a headwind is probably another good sign of a long ride. Around here, the mountains will occasionally turn the wind around, I have gone out on a ride that was essentially a square and had headwinds on 3 of the 4 legs. Crosswinds are pretty inconvenient too, they can seem like you are always battling a headwind