Marc Abel presents Parsers!
As you read this sentence, your mind identifies the words, punctuation, and the boundaries of the sentence. Good job - your internal parser is working well.
To write your own languages, you’ll need a parser - whether it’s a full-fledged Turing complete language, or just a tiny special-purpose Domain Specific Language (DSL). Even if you don’t, insight into how code is parsed helps you know and love your programming language better.