When coping with rejection, people vary in their resilience. But we can all learn to manage ourselves to be aware of our feelings, to be honest but discreet, and to move on if need be.
When planning your time, it’s worth being mindful of why you are doing each activity. In particular, prioritise tasks with mutual benefit for both yourself and others.
Human beings have the ability to place their thoughts in the past, the present, or the future. Some other animals have this ability too –