Roughly 85% of NCLEX takers pass the test on the first try while repeat testing passage rates(2017) are 45% according to NCSBN:

Meaning if you fail the first time around, you would definitely need to make the adjustments necessary to pass the next time because the computer has adaptively figured out your test taking capability. Maybe take a different approach to your studying, doing more practice questions, studying the materials, knowing your medicines, re-reading the rationales, but MOST IMPORTANTLY SLOW DOWN AND READ THE QUESTION! Such an easy concept but the reason we miss most our questions.