It sort of depends on what you mean by can't reproduce without looking at hints.

Like, even now if you asked me to write a number guessing game in a language I've had to use a lot (Java) I couldn't do it straight from memory. I haven't needed to read stdin manually for a long time so I'd have to look at the class and docs to see the best way to pull in a line and parse it into a number, I don't remember the specifics of the Random class either, so I'd need to double check the methods available and if they produce inclusive or exclusive ranges.

To me that's normal; I understand the program flow and what needs to be accomplished, but the specific classes and methods are something I don't keep with detail in my head, using the docs and keeping the language reference handy is normal, in my experience.