When you are 20 with something, you don't usually think about your 40. However, it always better to follow small advice at a young age in order not to face a huge problem later.
The risk to have skin cancer gets higher with age. However, if you care about sunbathes since a young age and protect your skin from UV rays with creams or lotions, the risk will be lower.
In pursuit of money, great career and fun we forget about the pressure on our psychological health. The statistics show that the largest number of suicide happens between the ages of 25 and 34. So, you’d better check everything with a psychologist from time to time.
Nowadays we do know how bad cigarettes influence on us. However, a lot of people are addicted to that bad habit for whole life and then faced consequences. If you do smoke, you’d better stop at 25, than being sorry at 45.
We all were young, of course, we want to have parties, a lot of alcohol and so on. I don't tell you not to drink at all, but your liver will be thankful if you do not poison it too much at youth.
Knowing your family deceases will help your doctors in the future to give you the right treatment at the right time. The more information you tell to your doctor, the more specific and correct the treatment will be.
In the end, I would like to say enjoy your life, but be careful and watch out your health from a young age.