The part where players invent unpowered human flight, and the part where they use the HEV suit’s optical zoom to look at a butt, are the two defining acts of the hardcore gaming zeitgeist.
YouTube commenter nobody960814 explains the trick:
“To prevent bunny hopping, valve created a system where repeated jumping should slow you down. Unfortunately they implemented it by applying a force on you in a direction opposite to the way you’re facing, not the way you’re going. So by bunny hopping backwards, you can accumulate ridiculous momentum.”