After 4 years of professional programming the most important thing that I learned is "user is stupid".
Once I modified old code that was summing salaries (I added extra column to the result), nothing else. My result was rejected because all salaries was empty. Period of data was from first day of the month from user selected date to user selected date. It turned out that user was selecting 27th day of the month (it was 27th then). I responded that salaries have full month period, and you'll have to choose end of the month... And then shitstorm began, that I messed up previous functionality. I tried to explain, but it wasn't working. It ends up with user selecting any date and I'm doing end-of-the-month in the background^^
It's my first rant, welcome to you all :)

I've learnt quite the opposite: usability is paramount to everything!

Welcome :)

I think you learned the wrong thing from that encounter. As developers we should never expect the users to do our work for us. We should never do the easy thing and expect them to have to learn how to do stuff.

It seemed that you came to a good and workable solution in the end, but one could argue that it should have been made that way the first time (not your fault, obviously).

Other examples are stuff like how we format dates. Why should the user be forced to input in a special format when computers are very good at converting stuff? Just because the devs are lazy, that's why.

We live in 2016, UX is everything, my friend. If you haven't already gotten it, you will be forced to. I recommend Dave Platt's books "Why software sucks" and "The Joy of UX" to get you on the right path. Good luck! :)

@uxmedic I'll check out that title you mentioned, but bottom line that user common wants to have something done right, but even user himself don't know what this right means (I mean results, not tech)