A good friend of our family went into a coma for half a year. Finally, when he woke up, he was stunned why his wife looked so old. He actually lost the last 15 years of his memory, and the memories never came back.
He skipped from no mobile phones to smartphones, to laptops. Everything was new to him. Being stuck in the early 90s but actually being in the 2000s, there was a lot of change to handle. But learning you missed all your children growing up was the hardest for him.
On a brighter note, my ex-wife at the time stood beside me the whole time and no we are back together and closer than we ever were.