Below is an instruction that describes a task, paired with an input that provides further context. Write a response that appropriately completes the request.

### Instruction:
Read the following poem and explain the message.

### Input:
Those who linger in the past
Sad reminders of what will not last

### Response:
The poem suggests that it is unwise to cling to the past, as it is a source of sorrow and ultimately transient. The poem encourages one to take the lessons of the past and to move forwards, embracing the future with optimism.