Well, at least you know for sure it is a string, unlike with a couple of languages I've had the misfortune to use in the past year or so where you really do need to check what the hell you ended up with ;)
I have the great fortune of dealing with YAML every day. The sheer number of ways in which string literals can exist is eye-opening, as is the interpretation differences across libraries. That the YAML spec has not been updated in a decade is icing on top.
Ideally there should only be one scalar type (strings), two ways to represent strings (simple | multiline), just one way to represent mappings and lists. No nodes/anchors, no "YAML is a superset of JSON" silliness and absolutely no implicitly typed scalar values.