"He seems determined to make a trumpet sound like a tin whistle"

This quote by Aneurin Bevan is a metaphor for someone who is trying to do something that is impossible. It suggests that the person is trying to accomplish something that is beyond their capabilities. The metaphor of a trumpet sounding like a tin whistle recommends that the person is trying to do something that is not possible, which they are wasting their energy and time while doing so. The quote indicates that the individual is being excessively enthusiastic and is not reasonable in their expectations. It suggests that the person is not being reasonable in their objectives and is setting themselves up for failure. The quote is an alerting to be sensible in our goals and expectations, and to not try to do something that is difficult. It is a reminder to be practical and to not waste our energy and time on something that is not attainable.