It's not possible to do everything, but people don't like to say 'no' for a range of reasons €“ perhaps because they fear the other person will get upset. Your personality type also influences how you interact with other people and whether you're happy to take on extra work 'just to please them' or not:

• An assertive person will stand up for their own rights, but be sensitive to others. They will deal with stressful situations and will move on. They have a strong self image, are direct, honest and use appropriate communications. They are often respected by others and will act to build others up.
• An aggressive person is self-centred, is often stressed and will stress others. They have low self-esteem, resulting in the need to dominate, and are direct to the point of bluntness or intimidation. They like to be respected and will often put others down.
• A passive person is concerned about others, to the point of personal detriment. They often have low self-esteem, resulting in subservience and indirectness. They may be stressed internally, though this may not always show. They act to build others up, even at their own expense.

Which character type are you closest to? Knowing this could help you to operate more effectively.