I think that's totally normal think...
don't think about **** like that
Ouch, sorry that happened. Welcome to the forum and thank you for the question. How much of a bang is too much? That is going to be different for everyone. The good news is that your head has a protective bone structure to help protect it. Most head injuries like you describe are not severe and pass fairly quickly. However, it is beneficial for everyone to know what the signs of a concussion are. There are rare cases where a single hit to the head causes cerebral hemorrhaging. That's rare though. For a mild head bang, normally, within an hour, you will feel better. If you don't, then see a doctor, go the urgent care or ER. Symptoms to look for and monitor include headache, dizziness, confusion, fatigue, nausea, slurred speech, ringing in the ears, temporary loss of consciousness, and amnesia about events leading up to the injury.
So, hopefully you recovered nicely and all is well. See your doctor whenever you have doubts.