My pet hate is going out on a ride into a head wind and coming back on a circular route still into a head wind! Work that one out!!!
Easy-peasy:
When you go out in still or light airs, your 18–24 mph movement generates a breeze in you face of ...
18–24 mph! Which on the Beaufort scale is a Fresh Breeze (generates moderate (1.2 m) longer waves. Some foam and spray. Branches of a moderate size move. Small trees begin to sway.) - this is force 5. Force 6 is a Strong Breeze (aka 'Yachtsman's Gale') and 6 is Gale force.
And this will always (on still days) be in your face. Simples
. Of course as you get tired and slow down, the winds drops but you are tired so feel as if it is still strong.
Best thing is - you can do nothing about it!