Charlie is a young boy who loves to play with his train wagon and listens to the music the train makes while on the railroad path. His father wants him to be a pilot one day but he prefers now not to even think about what he would like to be. His teacher is a lovely female and loves quiet-silent times at reading time with her pupils. Charlie likes to read the story "A happy Lemon tree" because it teaches him how it grows and when he finishes the story, he goes rapid to the playground to play with his peers.
i had just finish my soup when out of nowhere a wagon pilot comes up to me and said "your rapid female mole has escaped again making a huge mud mess outside ." as confused as i was since me being a non pet owner of any sort i said "which one of your tiny pupil saw a mole playing in mud you must have got lemon in your eye may want to go take a look." the wagon pilot then went silent and to my surprise told me " ha you have been fooled there is no such thing as a wagon pilot and there was no dog i have come to your bathroom to take advantage of the music you are listening to on your toilet. even a baby would have found that out by now, you are quite an *****." after saying this the man walked out leaving not a trace
basically, the quote is saying to take the unlucky bad things and make something good outta it. when life gives you lemons means when life gives you hardships. you make lemonade means you make something good out of the hardships. Hence the meaning of "when life gives you lemons you make lemonade."