How about this spin then?
If you were to fear the reliance of others to wake you up. What about a tiny sealed bunker, entirely hidden to the world, you were GUARANTEED to get out. So no need to worry about waking up and being under a slab of concrete to a office building...
You stashed £100,000 in a standard savings account to accumulate. Again, knowing it would never go missing. Let's just say a 3% growth per year...
500 years would yield £51,500,000... A fairly large chunk of money, but then again, in 500 years this could be just about enough to buy a nice Ferrari!