""Nothing takes the taste out of peanut butter quite like urequited love." – Charles M. Schulz, Peanuts
Once I fell out of love and I could barely eat my cereal, berries and orange juice in the morning. Another time I fell in deep like and when I learned that the person who I liked actually liked me back, I couldn’t eat my cereal/berries/OJ combination then either. Apparently this "takes the taste out of food" theory works at both extremes.