Nothing makes one grateful for instant hot water for a shower more than discovering there is only ice cold water that isn't warming up.  It's a luxury I am grateful to have the opportunity to have on a near daily basis. And when the water is ice cold, because the luxury of the hot water heater we have isn't working correctly, I try very hard to keep it all in perspective - cold water isn't the end of the world, many people in this world only have cold water if they have any at all, and when I do have warm/hot water to not take it for granted.