Do not feel bad.. When you start to feel bad about it remember this;
One of the most common complaints about RV water heaters is that they only put out warm water, no hot water.... Of course, nearly 100% of these complaints (there are a few exceptions) all have the same source.. I call it the dog shower,, (The outside shower)
Many of these have a cut off valve on the shower head.
The owner opened the mixing valves, rinsed off whatever needed showering, then cut off flow at the head.. LEAVING THE MIXING VALVES OPEN.
Now that is one I have not done......yet.... But I have come close a time or 3