Summary
This quote suggests that it is more beneficial to be a critical and honest friend, even if it means being a source of discomfort or disagreement, rather than simply agreeing with everything they say or do. Being a "nettle in the side" implies offering constructive criticism or challenging ideas to help them grow and improve. In contrast, being an "echo" means blindly echoing their thoughts and actions, which hinders personal growth and can lead to a stagnant, unchallenging relationship.