The idiom "be up on" means to be well-informed, knowledgeable about something, or to keep oneself updated about a particular topic. It is used to describe someone who is keeping abreast of the latest developments, news, trends, and events in their area of interest.

The idiom "point blank" means to ask a question directly, without any hesitation or indirectness. It is used to describe someone who is being asked a question and responds quickly and honestly.

The idiom "Van Gogh’s ear for music" means having a highly sensitive and appreciative ear for music, or being able to appreciate music on a deep level.

The idiom "keep your hair on" is a phrase used to encourage someone to stay calm, collected, and focused during a stressful or difficult situation.

The idiom "fill the bill" means to meet or exceed expectations, requirements, or a standard set by someone or something else. It can also mean to completely satisfy or fulfill someone's needs or requests.