PHP started life in 1995 as Personal Home Page, a Perl like scripting languages for dynamically building webpages on a server. Since then the community has developed the language into the most popular server-side scripting language on the web, and it is now presented as PHP: Hypertext Pre-Processor.
I first used PHP in 1999, to build a very basic website for a client, but didn't touch it again until 2003 when I learned it to get a placement during my degree, and since then I have never stopped.
I love PHP because it has everything built in, so there is generally one native way to achieve something, which promotes consistency and means that when an update is released, all the code you have ever written is now better, and there are no issues with libraries being abandoned.
PHP tends to get a bad rap as a poor quality language. PHP is not very prescriptive on how you should write it, that coupled with the huge user base, meaning it tends to be the first server-side language that people learn, has resulted in a lot of people producing low quality code, and giving bad advice.
The truth is that you can build crap in any language, but PHP is a modern, secure, performant, and versatile language, that is well supported, continually improved, and proven in the real world. That's why I love it and have used it throughout my career.