Old age creeps up on you. You may still feel fit in your 60's, but when you get to the 70's, you can definitely feel it in your bones, joints, and movement. After that, the decline accelerates. The other thing far more dangerous that creeps up on you is sin. With the advance of science and technology, people falsely believe that mankind can do anything. The convenience and ease science and technology have brought to life make it easy for us to forget about God. Self-glorification results in godlessness. I have lived long enough to see the rapid decline of morality and indulgence in self-gratification. What creeps up unnoticed can surely sink us.