Большой русско-английский фразеологический словарь
Ф33
ПОЧЁМ ФУНТ ЛИХА узнать, знать, понять и т. п.collsubordclauseInvarfixedWO
(to know, learn) what severe hardship is (by personally experiencing an ordeal, hard timeetc): what real trouble (misfortune, suffering, miseryetc) is
what hard times are (really like (all about)).«Жена воспитывалась в детском доме. Сирота... Она с детства узнала, почём фунт лиха стоит...» (Шолохов 1). "My wife had been brought up in a children's home. She was an orphan. .. .She had known what real trouble was since she was a kid" (lc).