From GMod Wiki
|Description||This function is run every tick.|
- Think() is not intended to be used for drawing HUD effects. It is suggested to use DrawHUD() instead.
- Think() runs every tick so long as the player has the weapon drawn, even while the game is paused. It will stop running if the player switches to another weapon.
- Be careful what you put here, as it is run every tick, and a lot of code may cause lag.