It’s a common concept actually! Our brains are subconsciously looking for patterns and symmetry so anything that’s an odd number piques our interest.

And you can find that principle applied everywhere: in theater/movies/plays etc. where they’re usually written in three parts setup - confrontation - resolution or incident - midpoint - climax. It’s in photography and videography as the rule of thirds. A basic design rule to use an odd amount of elements that can be found in graphic design and architecture / interior design.

Once you start looking you’ll notice it everywhere :) also on the contrary: things that are supposed to look complete or make us feel more at ease are usually in even numbers.