In a jungle, there was a fierce dog. Once he saw a rabbit and started chasing it. After running for quite some time, the rabbit got away and the dog was left behind.
A fox was watching this and said to the dog – “Shame on you – it was just a rabbit and still you could not catch it?”
The dog replied – “Well, that is because I was running after rabbit for fun and the rabbit was running for its life”
That’s what is the meaning of “giving 100%” 🙂