Shy and timid? Redundant?

Please help me with this everyone. I read sentences like this:
He had the way of criticizing you that made everyone else in the class laughed at you. I must confess that I was really shy and timid then because I was the youngest boy at home. I can’t remember the number of times he reduced me to tears.

According to Oxford’s dictionary for advanced learners, timid is shy and nervous, which means that the phrase “shy and timid” is redundant, isn’t it? can everyone help me please? Explain it for me why the writer wrote like this?

It’s not a redundancy though the two words are very similar in their definitions.
Both terms can often be seen together.