What is the logical overlap between "re-invent" and "improve". When people say "don't re-invent the wheel" do they really mean "don't improve the wheel"? This s

What is the logical overlap between "re-invent" and "improve". When people say "don't re-invent the wheel" do they really mean "don't improve the wheel"? This seems unlikely to me. Of course, the "3000 BCE" retort is a good one and I hope to use it at least once in my lifetime.