Flying a crosswind landing doesn't stop when your wheels touch the ground. Here's how to maintain your crosswind correction, and centerline, from touchdown through roll out.
You just crossed the runway threshold, and the runway's width suddenly fills your windscreen faster than you anticipated. You quickly pull back on the control yoke, feel the airplane stall, and touch down hard the runway.
Carrying extra airspeed on final approach, and flying faster than the manufacturer recommends for your weight, usually makes it more difficult to land.
It's pretty much impossible to explain aerodynamics without heavily simplifying it. Aerodynamics is a field for engineers, based on differential equations that don't have much use in the cockpit.