I have mentioned several times that traditional financial systems allow for a 4%-ish annual withdrawal rate, which means that you have to have 25 years worth of your income/expenses saved up before you are able to completely live off of those traditional investments in a kind of perpetual way... .and so these are ways not to deplete your principle until it comes to a time that you might see that you ONLY have a few years left (to the extent that you might foresee your demise and then start to deplete your principle at that time.