To give over to the task or activity at hand, diving in full bore and getting severe with it. When you harness in to something it is your only focus and you are driven to completion with efficiency and clarity. Harnessing in can be applied to anything from creative endeavours to handy work, or even something boring like sweeping the rug. Drugs and alcohol can help to eliminate mental barriers that block the harness but are not necessary. Harnessing in is required for all works of greatness but can damage relationships and mental stability if one is always harnessed in. A so called genius walks a fine line between madness and harness. Make sure to rest your harness for maximum effect.

when you're hungover as shit after a spending a night drunk as a skunk