Getting fired stimulates a lot of emotions that can leave you wasted in an interview. Getting fired doesn't make you a failure. Getting fired implies a subjective judgment of you, not an absolute, objective one. One boss's fire is another boss's hire. If that sounds trite, it is nonetheless true.
People tend to forget it when they're suddenly left hanging in the breeze.
People get fired for lots of reasons. The worst is that you weren't doing a good job. But, even that is a subjective judgment. An executive I know was about to be dumped by his boss because in the boss's judgment, the exec wasn't performing well. Before the boss could actually fire him, two other departments in the company started bidding for the exec.