Choose the wrong project and many of your skill will not matter

I suggest a good rule of thumb for any learning project is that the project should involve something you DO or MAKE not just something you LEARN.

• Don’t just learn French, aim to have conversations with people .
• Don’t just read a book on JavaScript, build a functioning website .
• Don’t just watch lectures, do practice problems from the exam.
• Don’t just read philosophy, write an essay or discuss it with someone else.

This rule won’t guarantee you’ll avoid transfer issues. But it prevents some of the more severe versions of the problem.