Switched my bike over to fixed wheel this morning, mmm interesting! Made it to work with only one minor incident, stood up to sprint to the traffic lights then tried to freewheel only to have the bike leap up underneath me and nearly send me flying.
Lesson 1, do not attempt to stand on pedals when going fast.
The other one that nearly caught me out was trying to coast through corners. That could have been a nasty surprise.
My main lesson this morning is you have to think ahead a lot further and anticipate.