One component of health many neglect is trying to maintain flexibility. As you age, things will definitely go south if you don't do anything about it. Some people are naturally more flexible. However, this will degrade too with age and with no action.
I feel we are more advanced with respect to flexibility training than 20 years ago. Stretching the muscles cold? That used to be standard when I was in high school. Stupid. Never stretch a cold muscle. We also over did it as well with respect to how hard we stretched. All I can say is we were sure ignoring common sense back then.
Do you incorporate regular flexibility work into your training? If you don't, you should! There are so many resources for flexibility make sure you weed out the bad versus the good. Try not to go on information overload. Simple tends to be good. Remember that. It doesn't have to be complicated, take 2 hours a day, and cost an arm and a leg to come up to speed on a good basic flexility program.