Lesson #2: Trust your instincts.
This one should be rather short and simple.
There are so many dangers in a zombie apocalypse, and any one of them could kill you, that, you do not want to walk into a situation where they may be lying in ambush. All it takes is one wrong turn to find yourself in a herd, or a trap laid by hostiles, or attacked by a pack of wild animals, and wind up dead.
As such, you need to learn to rely on your instincts and try your best to detect when you’re about to enter an extra dangerous situation.
If you get a bad vibe or something doesn’t feel right, trust that. You’re instincts are telling you something, do not ignore them.
Avoid areas, abort missions, whatever you need to do if you think you’re walking into a disaster. Our instincts can be amongst our best assets, hone them, learn to trust them, and don’t ignore them.