Be (right) down (one's) alley phrase
To be something that one shows interest in and finds exciting.
Politics is right down his alley. He can talk about it for hours.
Trust me. That club would be right down your alley!
This book is right down my alley. I couldn't put it down.
This idiom uses alley in the sense of “one's own province,” a usage dating from the early 1600s. [First half of 1900s]
Used to refer to a person who is your enemy
He faced his sworn enemy.