Most of us were taught as kids that getting other people's approval is extremely important. I still remember how ashamed I was to get hauled to the front of the classroom for some infraction in first grade.
I wanted to be invisible in the back row.
As adults we still believe that making people happy is important -- especially people in positions of authority! We try as hard as we can not to get in trouble, even though we are adults and not little children. Our early training sticks with us!
I talk to job-seekers every day. I hear from brilliant, capable people who are embarrassed and ashamed about having been fired from their past jobs.
We carry a lot of baggage about the idea of being terminated from a job. We think it's a mark of shame, but it isn't.
Most people who are terminated (as opposed to getting laid off) didn't get fired because they stopped coming to work. They didn't steal anything. They did something far worse: they made the wrong person mad.
That is very easy to do. You can make the wrong person mad just by telling the truth when everyone around you is silent.
It's not a bad thing to get fired. It helps you grow a thicker skin. When you are told to pack your stuff and get out of the building, it reminds you that you can survive much more than simply being told to leave your job.