And yet he got drunk in the second episode.
The Psi 2000 virus (variant) worked by altering the density and composition of water molecules in the brain which interfered with their ability to communicate with one another. Like being drunk. (Alcohol gets between neurons and screws up the electrical connections between them.)
... Arguably the Psi 2000 virus did the same thing to Data's "brain" and interfered with the communication between Data's circuits. Sort of like getting a electronic damp or wet and the screen becomes all glitchy and the it sort of functions, just not very well.
This is different than "the game" which provided an emotional stimulant which Data was incapable of.