You turn on the shower. And you wait. And wait. And wait some more. Annoyed and unclothed, you ponder how much of your water and time is being wasted each morning.
Consider...
Installing your hot water system as close as possible to the water outlet that you'll use hot water at most frequently (often, this will be the ensuite shower). The shorter the distance between the HWS and the outlet, the sooner your hot water will appear.
Alternatively, instant hot water systems also solve the problem, albeit for an increased cost.