Several reasons. Mainly to do with weight reduction.
A morning shit is generally bigger (thus heavier) then a shit at any time of the day so you may have been lighter.
The weight of the BOV has been removed
The air entering the engine would be happier (i dont know how true this is cos i just made it up but) and also thinner knowing its not being used to make a psssssssssssstttttttt sound and generally piss off passers by
After that maybe you were on drugs/pissed and thought it was quicker?
You accidently got in the wrong car??
Dunno....

