Don't think too much about age.
Lots of my classmates are more than 40... They are excellent in studying due to their experiences and common knowledge.
Just start your plan, you will what you want and how to do.
You think you are old?
If
1) your kids graduated and became independent,
&
2) your home is free of morgetage
&
3) you have resonable deposit to support your retirement
you can say you are old.
Otherwise, your age means nothing.
Start your plan, even though you need to use 5 years to aim your goal/new career, you still can enjoy your life for 20 years!!!! ( Regular retirement age is 65)
you will find you don't know how and what to do even 5 years later if you are just keep thinking............
my english is bad.......but I am not allowed to type chinese now.