Anything can make someone behave irrationally. People behave irrationally more often than they behave rationally. People get into cars and scream when they know they're getting ready to crash. Like, didn't they rationally know that could happen when they got in? They didn't know they were in danger the instant they got into a car?
If people were completely rational the world we live in could not exist.
I have seen one one billionth of everything there is to see and it was all the same.