On the slightly more negative side: everything management tells you that's not in an email will have "never happened" when it's convenient.
When you have a conversation with anyone where you think a plan was verbally agreed on, before doing anything your first action is to go back to your desk, write it in an email, send it to them as confirmation and find at least 1 other person, ideally in your reporting line, which you can cc it too.
Because it doesn't take an actively malicious manager to screw you over - it takes literally anyone who suddenly needs to change history to their own seniors for it to fall on you, the underling.
EDIT: And the friendlier or more casual someone is, the more important this becomes.
When you have a conversation with anyone where you think a plan was verbally agreed on, before doing anything your first action is to go back to your desk, write it in an email, send it to them as confirmation and find at least 1 other person, ideally in your reporting line, which you can cc it too.
Because it doesn't take an actively malicious manager to screw you over - it takes literally anyone who suddenly needs to change history to their own seniors for it to fall on you, the underling.
EDIT: And the friendlier or more casual someone is, the more important this becomes.