A business never retires, a business continues indefinitely...that is the mentality you need to have when focusing on SFI.
Retiring from SFI is not an option. Once you are in it you are in it for life :)
Once you retire from active employment you still need to spend time everyday completing your daily tasks and building your business just as you did in the past to ensure that your business continues to grow and your income continues to expand in your old age.