Trying to fit two gallons in a one gallon jug

[rlandis]

Trying to fit two gallons in a one gallon jug.

[Anglika]

You are trying to fit too much into too small a space, whether physical or metaphorical.

"They want us to have classes of 35 children in rooms that can only take 20. Typically they want to get a quart into a pint pot."