1. The human brain stops growing at the age of 18.
Normally, human brain tends to grow rapidly. By the age 18, all the brain growth is expected to have finish (the brain connections). The growth is not referring to increase in size. The growth is talking about the interconnection of neurons. But technology has so much increased that the major thing that should end 18 years, to some people might finish at 25 years or less. Not all 18year old can be subjected to taking critical decision. But he/she is expected to be able to do so but the conditions around might simply hinder that from happening.
2. In the morning, a person is about 8mm taller than in the evening.
Taller in the morning than evening. Looking at the ligament and joint structures around the bone especially the spine (bone). When you are asleep they tend to regain their true self before they become worked out during the day and you come up with joint pain(knee) or back pain. Insignificant difference though. What other things do you think can cause the difference?