I once worked in a special needs class that consisted mostly of kids with Downs Syndrome and Autism Spectrum disorder. There were many patterns I noticed that ran through both groups, but at the end of the free period when we had to draw the students' attention back to classwork, one difference became clear: their attention spans.
Kids on the Autism Spectrum would drop what they were doing as soon as they were told that it was time for lecture. To these kids, making sure everything scheduled happened on time was important; if something came up and they had to skip math, they would be distressed -- even if they didn't really like math. In contrast, kids with Downs Syndrome wanted to finish what they were doing. If they were in the middle of a puzzle, they had to finish it. If they were watching a Youtube video, they couldn't hit pause until it was over. We'd have to keep track of their activities and anticipate when a good time to pull them away. If a kid was listening to music, we'd approach them five minutes before the end of the period and allow them one more song.
This is not meant to draw boundaries between diagnoses (not every person with one of these conditions will act like the kids in my class did), but it does illustrate two very different approaches to attention: time-bound and task-bound. Someone who prefers to stick to a schedule is more likely to have time-bound attention, finishing a task when it is time for the next task, even if the previous task isn't completely finished. Others may be more task-bound, preferring to finish one task before moving on to the next.
To apply this to yourself, imagine being a child reading your favorite book before bed. You are told that it is time to go to sleep, but you are in the middle of a chapter. How reluctant are you to put the book down? Regardless of how good the book is, are you willing to go to bed before the chapter is done?
Variable answers are expected here. A gripping mystery novel is going to treat your attention differently from a comic book, in the same way that activities you enjoy feel different from those you don't. A person's willingness to move on to the next task may depend on many things, including time spent or remaining in the task, time until you can return to the task, enjoyment, and rarity of the task. You may be more reluctant to leave a party if you are talking to a friend you haven't seen in months, or if you just started playing a particular game with them, even if your attention is typically more time-bound.
Stress can come up interpersonally when one person is time-bound and the other is task-bound. If two people are putting together a puzzle and it's time for dinner, one might want to pause to eat, while the other might want to finish the puzzle first. Similarly, if a person who is time-bound is waiting on someone task-bound, they may end up waiting longer than they expected, depending on what the task-bound person is doing. It is important not to act like one of these ways of viewing attention is "correct"; they both have strengths and flaws and places where they are more or less appropriate. Just as it may hurt to stop an important conversation before wrapping up because it's "time for lunch", it would be inappropriate to drag an appointment over time if one or both parties has another appointment right after.
Next time you find yourself in a battle between the task at hand and the next task, notice where your attention is drawn and why. Notice how fluid this is -- your willingness to be time-bound when you want to be task-bound, or vice versa. Your answers may differ each time you try this, or they may show consistent patterns in your behavior. And once you've noticed these patterns, you can better examine how that changes the shape of your life.