Why it is important to be resilient when experiencing setbacks?

It is important to be resilient when i experience a setback because it is important to get back on track with what I'm going at work. When working with my priorities list, i do get disturbed with phone calls and people at reception, so i do get interrupted quite alot throughout the day. I do get thrown off track when i get interrupted, but i always manage to get back to the task im doing and complete it.