The importance here is not that we have a "Doh!" moment, like, why did I not invest instead of spending on shorter term goals !? Rather it is to suggest that a useful strategy for the future may be to merely spend any substantial funds that are received as gifts on mutual funds or individual equities likely to provide good returns in the years ahead, just as they have before.
And if that means that we get to retire or attain other intended targets that much sooner, all the better. Nest egg assets that are left invested for potential rainy day contingencies, and so untouched for more day-to-day needs, may well in time grow to the point that we, like those whose generosity has been helpful to us in the past, are able to then "pay it forward" and make charitable gifts to our preferred beneficiaries, be they relatives, friends, or very worthy causes.
It seems, anyway, like this might be a good idea for us. Good luck with your own gifts received and opportunities for personal generosity on down the road!