I'm dizzy!
Even if it was sarcasm, what the hell, I'll chime in. Humidity, last I checked my engineering books, has no significant weight. On a day with 95% humidity, based on your logic, it should be more humid near the ground. Yet clouds, which often are near 100% just before it rains don't fall to the ground.
In a sealed room with constant temperature, the relative humidity is nearly constant at every point in the room. But, since temperature is the hardest to control, particularly in your home, a sudden change in temperature with high humidity can cause moisture to form (like on the mirror of your bathroom when you take a shower in the morning.) If that has happened, Rick's analysis is pretty good, moisture particles (H2O) do have weight and will travel due to gravity.
I'm exhausted - homeroom is over, now get to your first class.
- Gonz