Reference is important for LEARNING. If you know you can’t seem to get something right, reference it.
You’re ability to recall how something works without the use of reference is what you’re trying to achieve. Don’t mistake this as saying “You always need reference.”
It doesn’t mean you suddenly stop drawing from imagination as a result. In fact, now you can do more thanks to have LEARNED from reference.
Fun fact: Artists are always learning. They never stop.