I would like to share my experience of having a category II concussion:

within 30 minutes, I had a CAT scan and a MRI. Both cleared by neurologists.
(GET a CAT scan!! follow up on it!!)

3rd hour after the incident: I still do not have memories about why I'm even there biking, what month and date it is, and where I was BEFORE the incident.

5th hour after incident: memories about why I was biking comes back. Where I was BEFORE the incident comes back.

24th hour after incident: very sleepy. can't function much.

3 days after incident: still sleepy day. Feel very dizzy if my head is tilted in a particular angle.

SLEEP! A LOT! and eat almonds and nuts. It helps.

6 days after incident: sleepy phase gone. Test on reaction time indicates that my reaction time is significantly lower than before. Short term memory difficult to establish.

15 days after incident: reaction time is slowly recovering. Tilting no longer induce dizziness.

25 days after incident: short term memory test is recovering.

35 days after incident: fully recovered.