He likes to go down rabbit holes — he has to get to the bottom of everything.
Tips
usage
牛角 is literally 'ox horn', but it is best known through the idiom 钻牛角尖 (zuān niújiǎo jiān) — 'to squeeze into the tip of an ox horn', meaning to get bogged down in trivial details or to pursue an impossible line of thinking stubbornly.
