Question

Why is it important to credit your sources properly even if no one is likely to find out?

Answer 1

Because the machines can determine weather or not it’s been copied from another source (plagiarized)
And because if you do really good and it gets out into the real world.. you could get in a lot of trouble

Answer 2

Because if you are ever doing research, for instance when you have to turn in your thesis for your PhD, you have to pass peer review. Also intellectual data that is not yours has to be properly cited otherwise it is considered academic dishonesty.