Now what is only human, you might ask? Errors are. Among the other things. Making them is really easy to human kind. It is of course easy to every single creature in the world. Even our dog seems to learn from its mistakes. Well, to be honest, I’m not quite sure about that, but at least I’ve got an impression that it is capable to learn at least something. In a matter of trial and error, what do you think that matters?
I really am a strong believer of trial, not error. As a test engineer I’m urged to try out things; to try out to do the errors and thereby to find out if the software I’m testing has them. I might also try to find the errors by other means, mainly by doing things I’m supposed to do. But that one should be more rare case to find errors, regarding that me and the developer have been handed the same pack of requirements. Which is not always the case. And even when it is, the understanding of the requirements might as well differ from one to another. And that’s the way you find the errors in the process.
But what is important here is how we handle the errors. As a tester, I’d like the developers see the found bugs and defects as an opportunity to make better products. Not being ashamed even for the stupidest mistakes. I’m not there to point out who has been stupid or idiotic. No. I’m there to point out that the application is not acting the way it should. The guilt comes within the person who receives the bug report. Well, in a case that I’m not being that stupid and making an ass of myself and blaming someone for making stupid mistakes. Which I rarely do. Come to think of that, I don’t recall when that happened last time. Maybe yesterday while being stupid, but hey, that’s like ages ago.
The same applies to slip-throughs. They do happen. The fact is that a test engineer can never test everything. We should be testing everything that is important and needed. But then again, we’re also only humans. It’s not a good thing that such things happen, but it is normal. What cane we do about it?
We can of course start the blame game. Which is one of the errors I’d like to be capable of avoiding. But as I’ve said before, it’s only human to do even so. Even though that is really stupid. Regardless who you are blaming, whether it being yourself or whoever else, you’re pointing your finger strongly and firmly to a place where the error does not exist; it is only the symptom or manifestation of error you in that case are pointing to. And this one here is the thing:
1) When making mistakes, learn from it, don’t try to stop doing them.
2) Don’t blame yourself – even though that is human, too – well, don’t do that too much.
3) Guilt and shame prevent you from seeing the actual problem. Sometimes they lead you to make same errors again.
4) Don’t be ashamed of missing the first one, second one, and the third one.
By trial and error we learn to get the banana from the tree. Or the tree and the banana. Or strained hands. or as in this case a list of things instead of the thing. 
“Never give up your right to be wrong, and be sure to give others that right too.”
― Tim Fargo
“You never know what worse luck your bad luck has saved you from.”
― Cormac McCarthy, No Country for Old Men
Blunt Instruments Of Testing 