Now and then I hear someone brag about being a "multi-tasker"- being able to do several different things at one time. I never believe a word of it. Multi-tasking is a myth. What people actually do is switch rapidly from one task to another, with varying degrees of inefficiency.
People's attempt at multi-tasking doesn't impress me. What impresses me is people who are able to be completely present for a person or a task. In our hurried, pressured world it is hard to concentrate ones full attention on what others are saying or to focus on a single task. It is more likely we will be thinking about what we are going to say in response or flit from one project to another, which means we are not present.
I attend a lot of sessions that require my focused attention. Sometimes I go from one session to another. If I am not careful my thought processes will bleed over from one session to the next or I will anticipate the next session. When this happens I am physically present but emotionally absent.
The most important form of self-denial is denying oneself the thoughts and actions that prevent us from being actively present.