English: "I already learnt english at school, hur hur"

Maths: "I already know maths. 2+2=4, hur hur hur"

Physics/chemistry: "Oh, brainbox now eh? Mad scientist eh hur hur hur"

Philosophy: "What are you gonna do with that then? hur hur hur"/"so you just gonna sit around all day and think then? hur hur hur"

Any foreign language: "Why would you want to? Everywhere speaks English already"
Geography: "Oh can't you read a map then? hur hur hur"

Anything involving computers: "Yeah, that's good that. You'll need that, everywhere uses computers nowadays"

Any more?