Haha there are two different idioms in play here.
- "If life gives you lemons, make lemonade" - Make something positive out of something negative.
- Using Lemon as a descriptor of something, e.g. "I bought a Lemon", or "It turned into a Lemon" - Usually indicates that there was some unknown defect in the product, e.g. the car you bought stopped working after a week, or the house you bought on the cheap turned out to be made up of 90% termites and only 10% wood.
