I like to think that I am fairly technical and by extension reasonably clever, says the software developer. I can install Windows operating system, Linux, or even both of them side by side on a computer from scratch.
It took me a while to realize just what my problem was with the public transportation ticket machine in Stuttgart, Germany. The thing is that the machine has two numeric keypads, and when it is asking you for input you are expected to know just which one it is talking about.
It turns out that the machine manufacturer was either fairly clever or extremely lazy. The one keypad exists for answering mundane questions regarding your travel plans while the second one can only be used during payments.
I can only imagine that this did make the job easier for the manufacturer. They simply purchased some sort of payment subsystem from another company and without any integration popped it directly into the ticket machine. It is good for them, and it is tolerable for the locals, but a gigantic pain in the lower backside for any visitors to this region.