SUCCESS:

 At age 4 success is . . . . 

Not piddling in your pants. 

 At age 12 success is . . .

 Having friends. 

 At age 17 success is . . . 

Having a driver's license. 

 At age 35 success is . . . 

Having money.

 At age 50 success is . . . 

Having money..

 At age 70 success is . . . 

Having a drivers license. 

 At age 75 success is . . .

 Having friends. 

 At age 80 success is . . . 

Not piddling in your pants.