what have I done to my laptop?!

[VinegarDrinker]

I've clearly pressed/clicked something but no idea what! It's like ctrl is stuck on.

Clicking on links makes them open in a new window
Pressing a highlights
Pressing p prints etc

Help, how do I make it stop? (typing this on my phone)

[TickledOnion]

Mine does this sometimes. Try pressing the Ctrl, shift and both Alt buttons together. I can never remember the exact buttons to press but trying them all seems to fix it.