My experience is a bit different. My memory was hell right after, but the nurses told my wife that it was the chemicals used to keep my unconscious during most of my 6 weeks in ICU. They stated that they tended to pool in the fatty tissues and would take weeks to clear out. According to my wife the docs (neuro and psych) seemed to be preparing her for permanent damage and as a result a limited rehab facility. Nurses were right. The first few weeks were way foggy and I couldn’t determine day for night, and or where I was. They even asked me where the hospital was. I had no idea since I was unconscious during the transports to both hospitals. Once I cleared out, I seemed almost more focused and had very sharp memories. Like the brain had a 2 month vacation / rest. Although I had some very weird hallucinogenic memories that were quite complicated. Today, 3 years post onset, the nerve pain etc, and resulting poor sleep have been bothersome.
Good luck, and sorry for rambling about my experience.