What I've found is even worse: on medium-size personal projects I inevitably pass the wrong type to a function (or refactor and forget to change a call somewhere). Generally it does not fail until somewhere else, which relies on it being a certain type. So even though I know what my functions should take, I still spend a bunch of time tracking down the problems, which involves a printing out a lot of stuff because the error happened outside the current call stack. This is something a static type system would just prevent for me, and I've basically decided that anything beyond really simple stuff is actually faster for me to write in a statically typed language. (Examples in the past are a parser for a static site generator with a mostly Turing-complete language, and 3D model generators)