I had a minor accident on my second day in the US and had bruises and cuts on my arms and shoulders. Did not go to the doc since my insurance was not yet covered (at a university). I felt really sleepy after and my roommates told me I slept for 24 hours straight. For me, that sleep was the deepest I have ever slept. Felt like I had lost time. I felt much better after and the body had begun its job of healing and at some places almost healed it. That was at 22. I miss that level of healing now after 20 years.