Retirement isn't what it stacks up to be, the happiest bods in the world will tell you that they stumbled upon something that had them "consumed" for life.
I am 57, I wanted to be a pro pilot at 17 and had a great opportunity that the family talked me out of (cheap labour on the station).
Agriculture has been great BUT follow what you want.
The best statement in life I have ever seen was from Jimmy Connors (tennis player), he said at the age of 15 he had found something he loved, at the age of 35 he had friends who were like flotsam in the sea, directionless.
I have a mate who started medicine at 42 years of age so you have plenty of time.
