A joke comes to mind. Two peasants reaping crops and to pass time they play a guessing game. - I thought of something - says the first. A week passes by

A joke comes to mind. Two peasants reaping crops and to pass time they play a guessing game. - I thought of something - says the first. A week passes by - Is it deoxyribonucleic acid? - Yes. But how did you know? - I had time to think.