1. The article discusses some unintuitive features of the C programming language and provides historical context for why they exist. 2. Specifically, it explains that "double" was originally called "long float" in early versions of C, which is why %lf is used for printing doubles. It also discusses why equality operators have higher precedence than logical operators. 3. Additionally, it notes that C was originally designed for UNIX system programming where floating point was only supported in double precision, so the math library only supports doubles rather than floats. 4. Finally, it explains that the name of the C compiler output file, a.out, comes from the original UNIX assembler output file name.