Anyone experience these every so often?

Just this past Sat i was on the couch napping. Got up fairly quickly, walked into the kitchen (25 ft away), picked up my Ipad and that was the last i remembered. Woke up to my son looking down at me yelling for my wife in a pool of blood. Not knowing where i was, i got on all fours and could not get up any further. the blood was dripping from my forehead, down my face and to the floor. My wife helps to the chair and says we;re going to hospital. Still not really comprehending any of this, i got up and followed her to the car. In the hospital from Sat afternoon till Sun relaeased at 3pm. Suffered a concussion, 6 vertical stitches from the top of my forehead into my hairline, bruised nose and swollen temple. docs ran several EKG's, took blood 4 different times, chest Xrays and do not know what caused this.

Very freaky experience!