The human heart is like a water pump.

It looks fine; it sounds fine. But if you don’t look after it, if you’re always running hot, or your system’s full of shit, your impeller blades wear down, your bushes go, your gaskets start to leak. But it still looks and sounds fine, till suddenly one day you find yourself stopped at the roadside, boiling over. You open your bonnet and you say, shit, my water pump’s fucked.

Look after your heart.