Absolutely. I don't to have to remember which variables are safe to change and which ones aren't; I want the language to remember that, and to remind me if I g

Absolutely. I don't to have to remember which variables are safe to change and which ones aren't; I want the language to remember that, and to remind me if I get it wrong. Sometimes I might want to use a library in a way its author didn't previously intend, so I might then want to modify a variable even if it's marked as const. It makes sense in a dynamic language to have a way to bypass the checks (like Ruby's "send" to access a private method). But that isn't an argument for discarding checks altogether.