Regular expressions are often very intimidating, in part because they are so information-dense and because a symbol's meaning can depend entirely on context. Unlike many things in computer science, regular expressions actually get easier (at least in my opinion) when you go back to the backing theory.
Regular expressions (regexes for short) are like equations for text. Specificaly they describe some number of similar pieces of text such that if we have some text and a regular expression we can ask "Does this text contain the pattern described by this regex?" We'll assume the text we want to examine is some basic english, which strangely has only the letters 'a', 'b', and 'c'. I'll surround regular expressions with forward slashes (/), and text with double quotes (") To start of with, we'll have only a few tools for doing that: