Just a moment ago, Cass was revising at the dining table for her Science test tomorrow.
Me - remember to take your fish oil ok? Fish oil is very good for your brain. You really need a lot of brain power now so that you can remember everything that you are studying for your exam. Fish oil is also good for your eyes, can prevent cancer, prevents dementia and good for your immune system.
Cass - mum, if fish oil is so good and can prevent so many diseases, why do fishes have such a short life span?
Me - because fishes are animals and animals can't live as long as humans.
Cass - yeah I know, but if fish can help humans to prolong their life span, why can't it live as long as humans too?