Majority of the hacking tutorials:

Tutor : Now we are going to set up two virtual machines to practice our hacking.

Me : Yes finally some useful practicals

Tutor : First one is Metasploitable

Me : What? This OS literally has its name derived from exploitable! How would it be useful in real life! But its ok, there is one more OS for practice, i am sure that one will be better.

Tutor : And the second one is "Windows XP"

Me : *MOTHERFUCKER!*

P.S.: I understand its not the case for all tutorial and it is somewhat necessary, but still it gets me a little.