Flexibility is not as practiced since it's viewed as not as important as things like aerobic and strength. Flexibility should be incorporated into everyone's fitness routines, since exercises that train your flexibility help prevent injuries, back pain. and balance problems. To incorporate flexibility into your routine, you can practice certain stretch exercises.
According to the Red Cross, people who have tattoos can donate blood. It's just that they would have to wait for 5 or 6 months after getting a tattoo before donating their blood. Same thing if you get your ears pierced.