Hopefully I'll compile in future a list of "most annoying things beginners do" (and perhaps even later the same about "seniors do") - but for now here is one recent.

So my side-project is a small site with programming problems and simple checker for users' answers - and yesterday I got the post in the forum saying

It strictly seems me that there is a BUG ON YOUR SERVER

Moreover, this dear fellow posted this to several past threads about the same problem. I initially thought something was completely broken! (no)

Now what it was about?

One of the first task is like this - we are given integer number and are asked to multiply or add something several times, then at last take modulo and print result, e.g.

input data:
5
+ 3
* 7
+ 10
* 2
* 3
+ 1
% 11

answer:
1

This fellow had written the code, tested it on small example, executed on larger example given by the site, sent the answer. And it was WRONG.

It's not exactly the same as "Works on my machine" problem. It works on either machine with small numbers and don't work with large numbers.

Fellow even suspected there could be problem with value overflow and used double values (this won't help, server generates example which is large enough).

I tried to answer, to explain - but I'm not sure it could be helped...

Most irritating is that:

• problem statement asks to read carefully dedicated article on modular arithmetic
• it was solved by 4000+ users already (with no "bug on server")
• there are multiple posts on this task in the forum and search box to find them

Conclusion

Well, what I want to say. One of the important things to become a good developer (and have fat salary) - learn to be more logically self-critical. When we are paid for work, we can't just complain to boss that "there is bug in compiler / server / linux / everything-but-not-me" (unless we nail it down).