If seeds could think, the one that fell into the builder's yard must have thought itself really unlucky.
It had drifted down through chain link fencing, perhaps rolling off angle iron struts. Eventually it landed on the rubble and rubbish strewn soil - under two discarded metal gates, each of which would have needed two strong men to put them there.
What chance did it have? What could grow under all that iron and debris? It should have given up.
Instead it tried. It grew. A little shoot not big enough to move any of the rubbish on top of it, so it grew around it. But surely those great heavy gates would stop its efforts coming to anything.
But it grew some more. It found spaces, grew through them, grew around them, and joined up on the other side of them. It kept going.
Now there's a twelve foot tree in that space. Metal struts are trapped inside it's trunk and wires run through its branches but now it's the gates that are stuck. They've been lifted off the ground but they can't be moved, they have become part of the tree.
The gates can only be seen now because it's winter, but in the summer the branches of the tree fill their little corner of the yard and all you can see is swaying greenery.
The little seed kept on trying, even though the soil seemed barren and the obstacles seemed too great. It grew in the most inhospitable place and never gave up until eventually the people who said it would never happen looked at the tree and were amazed.