This is an extreme example, but one I now live in daily.
My current full-time-ish gig is working on a pretty enterprisy system for law enforcement. To this date there hasn't been a single feature request, or bug fix that took more than 16 hours of development time. And so I know that I can typically finish something within a few hours to a day of receiving the task. UNLESS my manager wants to discuss ad nauseam what he means when he says "intersect an array". Or get stuck in 2 day long code reviews where my manager makes me sit behind him while he goes over every single line of code that changed, then gets side tracked and starts checking emails, chat messages, text messages, calling other developers in to check on their statuses, and even watching youtube... while I'm stuck in his office waiting on my code review to be done so I can go back to my 5th day of trying to complete a task that would have taken only a couple of uninterrupted hours. /rant
And this is why I pay $120 a week for therapy.