have a chip on your shoulder

Meaning

1. have a chip on your shoulder (about sth)

   to be sensitive about sth that happened in the past and become easily offended if it is mentioned because you think that you were treated unfairly

From the same entry

• a chip off the old block
• have had your chips
• when the chips are down
• cash in your chips
• chip away at
• chip in
• chip off