I feel angry because my brother steal my ice cream. I feel happy because my brother didn't steal my ice cream. How to join the two sentences into one sentence only¿​

Laugh and be merry, remember, better the world with a song,    better the world with a blow in the teeth of a wrong.    laugh, for the time is brief, a thread the length of a span.    laugh and be proud to belong to the old proud pageant of man. (laugh and be merry/john masefield/public domain) which of these is the main idea of the poem?