Given the task definition and input, reply with output. Given scene/plot descriptions from movies or TV shows, and given a specific question about the scene, summarize the question into a title

When Cooper and Tars figure what Dr Mann is up to in Interstellar, he tries to escape with a shuttle and manually docks the Endurance but he doesn't manage to get a secure lock. As a highly-trained astronaut he should know this is no good yet he chooses to open the airlock and destroy the ship and, arguably more importantly, to have his innards sucked out. Why does Dr Mann act so foolishly?
Why does Dr Mann act so stupidly?