A popular language with a lot of documentation and user comments has a lot of instances of a common phrase? Python and Java also have pretty heavy use of the phrase, proportionally speaking (since PHP does have a massive amount of built-in functions):

https://www.google.com/search?q=site%3Ahttps%3A%2F%2Fdocs.py...

https://www.google.com/search?q=site%3Ahttps%3A%2F%2Fdocs.or...

I find this phrase to be much more fun:

https://www.google.com/search?q=site%3Aphp.net+"wtf"