When the wind is over 40 km/h and I've been riding against it for a while I find myself swearing out loud at the wind. Particularly if its a gusty wind, up a gear, down a gear, ... If its a recreational ride I almost always head upwind first. I always have to force myself to keep going further into a strong wind because the return trip will be so fast I'd regret wimping out too early.

Last spring we had a ride with a 60 - 70 km/h headwind. Heading out the best we could do in the drops was 11 km/h. Needless to say we didn't go far.

Riding down wind in really strong wind is quite the experience. You never go faster than the wind, so there is no wind rushing past your face, creating a strange silence. All you hear is the rustling of grass, drive train noise / tire noise.