The term from the old days was 'souplesse'. Conversely, every spring you can spot riders who spent the winter on a fixed exercise bike: stomping at the pedals, bobbing their torsos and swaying their shoulders.
Your brain will imagine when you ride off the edge of the rollers you'll go zooming across the room - but no. You and the bike have no momentum, and the momentum in the spinning wheels isn't enough to even budge you forward.
It was said that Dan Henry (yes, THE Dan Henry) could strip down to his skivvies while riding rollers, and he would demonstrate this at bike rallies.
I saw him do it in person.
You will crash, and as stated it will be a zero speed crash from slightly higher than normal. Probably a real hilarious looking incident that might involve minor injuries.
The incredible boredom of riding rollers in the winter convinced me to gear up and ride outside. I made my own studded tires with sheet metal screws. Riding in the snow is a super workout; all that sliding around helps bike handling skills.
God I had rollers.
Have fun.