If something is your "bugbear," it means it's your pet peeve or a recurring annoyance that bothers you consistently.
For example:
- "Loud chewing is my bugbear; it drives me crazy!"
- "Traffic jams are my biggest bugbear when commuting to work."
Similar expressions include "pet hate," "thorn in the side," or "annoyance." These phrases convey the idea of something that persistently bothers or annoys someone.