What does it mean to start your career in middle age, but you are afraid of hard work in your later years?

It means that people have achieved something in middle age, but you begin to enjoy yourself, revel in wealth and don't strive for progress, then your later life will be very hard, very hard.

This sentence tells us that people should not disturb this order when they should do things, otherwise it will have a great impact on your life. Bitter before sweet, don't neglect yourself.