every rose has its/a thorn

proverb There is rarely a good or positive thing, event, or circumstance that is not accompanied by some aspect that is negative or unpleasant. A: "I can't believe the amount of taxes I have to pay on my lottery winnings!" B: "Every rose has its thorn, eh?" That's just how life is, honey—every rose has its thorn. You have to take the good with the bad. I was so excited to buy this house, until I realized how much work I'd have to put into it. Ugh, every rose has its thorn.