Apples are deceiving

I bought a bag of apples in my weekly groceries on the weekend and the apples looked all green, juciy and glossy. I was quite impressed with the bag I chose. However, when I went to have one for my afternoon tea at work... It was not at all how it looked when I bought them. Sure it was still green but it didn't look as juicy or as glossy. I took a bite and to my horror it was all mushy and sour.