It's just a part of human psychology, once you've decided to do something it can result in tunnel vision where obvious indications that something is wrong get i

It's just a part of human psychology, once you've decided to do something it can result in tunnel vision where obvious indications that something is wrong get ignored. It can sometimes be hard to take a step back and re-evaluate. We've long observed the same thing in airplane pilots. When they get takeoff clearance they can get so focused on getting the plane into the air that obvious signals of deteriorating conditions during takeoff get ignored. The Tenerife accident is just one example of this.