Picture this. You're on holiday in the Algarve. You don't speak Portuguese. You're driving a rental car that is low on petrol. You see a petrol station ahead, with queues on either sides of the pumps. Cars behind you are also signaling to enter the station. You now need to pull in and get into the queue that will put the pump adjacent to the filler cap. But which side is it on?
You stop short of joining either queue. The car behind edges forward impatiently. You strain to look in the wing mirrors to see if the filler cap is visible. It isn't. You struggle against the seat belt to try to twist yourself out of the window to see if you can see the cap. You can't. The driver behind you has had enough, he veers rapidly around you shouting something that may either be advice about which side your filler cap is on, or a reference to your parentage. He now pushes in front of you. Your blood pressure begins to rise. Somewhere in your cranial cavity there is an artery with a very thin wall. Deciding enough is enough, it expands, balloon-like, then...
You wake up in the recovery room, muttering incoherently, without the use of one side of your body. And why? Because you were not aware of the hidden secret of one of life's mysteries. For years, neurosurgeons have successfully lobbied to prevent the widespread distribution of the information I am about to give you, freely, without even an iota of anticipation of being remembered in your will.
Look at the petrol gauge. See the tiny little pump? While the pump gives a pretty good indication that this gauge is about fuel, not water, this is not it's prime function. See the hose coming out of the pump? It might be on the right of the pump, or on the left. Is this just artistic licence on the part of the pump-icon designer? NO!
The secret is secret no longer. The filler cap is on the same side as the hose!
Pass this unto each successive generation. You will be held in high esteem and your wisdom will be revered. And I take back what I said about being remembered in your will!