In my case, the most unrealistic deadline was when I was put on a project for 30 person days in 2008. The project had been running for about 6 months at that point.

I spoke to the project manager about my tasks and she told me to finish the fat client. So I immersed myself in the sources. And I was horrified to realize that not only was it not even a POC, but the performance was lousy to say the least. It took about 70 (sic!) seconds to start the program, read in about 20 records from a database and display them as a hierarchical structure.

I asked the PM when I was supposed to have finished my work, and her response was, "Yesterday."
"Very funny," I replied.
"No, really," she said, "the deadline was yesterday."

It took me an afternoon to speed up the fat client startup to 6 seconds. And then it took us another two weeks or so to identify the processes in discussions with the technical project manager. Because that didn't exist yet either.

About 1.5 years after the deadline, the software system - consisting of the fat client, mainframe modules and purchased software - was stable enough to be rolled out.

I always try to make problems more ... interesting, fancy, challenging. As soon as it gets boring, my mind is wandering.

Like now, when I wrote like a gazillion stored procedures, connected them to the back end classes, connected them to the new WCF service methods, connected them to the front end ... That's when I try to do anything but work.

I was so bored the other day, that I wrote a fat client in C# to calculate happy numbers. I used BackgroundWorker class, because I was hoping to be able to cancel the calculation process. It turned out I couldn't. Rats.

Out of pure frustation, I wrote the same program in Java using Swing and SwingWorker. Here, the cancel feature worked just fine.

And then I had this "Wait ... What?!" moment, when I realized, that one of the programs was incredible slow. So I rewrote both codes, so that they used the same algorithm and similar classes. I compiled the C# program as release and ran it stand-alone, while I started the Java application from within the eclipse IDE.

The C# program needed 42.681 seconds for 100,000 happy numbers, while the Java application completed the same task after 0.986 seconds. The result sets of both programs are the same.

Maybe I need a new PC (2007, 64 bit, 8 GB RAM, Windows 10). Or I'll get rid of C#.

We had a priority 1 incident (= the complete basis of our business is at risk, nobody can work anymore). The reason: at least 50 fax machines didn't work anymore ...

You're laughing? Well, in the department next to us, they still use dot matrix printers.