I don't know about being "hard headed" but whenever I'm trying to fix something, I need to concentrate Fully on the task. Having someone hovering nearby asking questions, etc., just extends the "outage". I've been that way forever. When I was working, if some manager kept interrupting my thought process, I would simply stand up and engage him in a polite conversation. It usually didn't take long for them to realize; that the longer they "bugged" me, the longer their computer would be down.
The same holds true around the house. If my wife finds a problem she informs me, then gives me some space and time to investigate the issue.