No doubt there are people reading this message who speak Japanese who will correct me, but ... 30 years ago I studied Japanese a little bit. One interesting feature of the language was that once a subject was introduced, there was no need to restate the subject if it hadn't changed, resulting in paragraphs like the one which intrigued you.

"I have used PHP for years." The first sentence establishes the subject is "I".

"Like it." etc Because this sentence doesn't have an explicit subject, it is implicitly the same one, "I".

As I recall, "wa" and "ga" were the Japanese particles which established new subjects. Say you wanted to talk about Bob's new car, you'd say something akin to "About Bob's new car, is expensive. Arrived last week. Has poor gas economy."