When something does not work, you do not have a predefined set of "these things I did are 100% right I am sure". Thus you can spend ages poring over your code closely wondering why the data is being repeated in your table. And spend time nodding in empathy (without getting a solution though) when you find other users complaining about the same problem in online user forums. Only to discover at the end of 2 hours that the reason why the data was repeating was not because you did the new technology wrong - you were 100% right there. However you had accidentally added the same data twice to the display list in the first place. Ugh :-(!
But the brighter side - the stuff I am working on is still on the (b)leading edge of technology. So when I get some customized thing to work, I can take full credit for coming up with the solution. Thus, in between all the hair-pulling, these days, my work day is also littered with "ah-ha" moments. Kinda makes up for all the times I feel like kicking the computer I guess.