Imagine this scenario: After a week of hard work, you send an important report to your colleague. His task is to edit the wording and make a few key decisions to finalize some of the content. The deadline is still three weeks away, but you hope he'll finish it early because you'll have more work to do once he gives you his input.
Your colleague, however, delays making the changes. After numerous reminders from you, he sends it back the day before your deadline. This means that you have to rush to complete your final changes in time. His delay has caused you some serious stress, and it's not the first time that this has happened.