There are different tasks for which different approaches work best.
If I am doing development work, heads-down programming for hours at a stretch works well. I know what I am trying to accomplish, and roughly what will be required to achieve it.
Handling user problems is a totally different thing. Sometimes the solution will be immediately obvious to me, but when it is not, I have no idea how much effort will be required to solve the problem. It may be relatively simple -- perhaps the user has data problems, or has done something out of sequence. It may be complex -- a software bug that hasn't shown up before. What can be frustrating is that I don't know in advance how much effort will be required. My impulse is to get the problem out of my hair as quickly as possible so I can get back to other tasks. And since I have to account for my time, I don't want to spend hours debugging and tracing code only to find out I have wasted my time. It is necessary to maintain perspective, and not get sidetracked. A heads-down approach doesn't work so well here. It can be useful to take short breaks, and return to the problem refreshed.
An analogy would be that development is like driving to a distant city. You know where you want to go, and even if you haven't been there before, you know how to read a map and follow signs. You just have to put in the hours behind the wheel, paying attention so that you don't get lost or have an accident.
Dealing with user problems is like trying to help someone who has lost their keys. You start by asking them to check their pockets, or recall when they last had them. If that approach fails, you may have to help them search. If nothing turns up, you may have to get a locksmith to change their locks and give them new keys.
Today I had a user problem that turned out to be caused by two separate software bugs. I was pleased to be able to get it solved before my weekend, and I think that taking a few short breaks and not being totally focused on the problem paradoxically helped me solve it more quickly.