Planting an Apple Tree

Our lot has good drainage.  The soil is likely compatible but the trees need 6-8 hours of daylight to thrive.  A gardening pro suggests checking  for sunlight on the summer and winter solstice then locate your plantings accordingly.  Today is September 21. I have studied the yard for sun and shade and I think I know what the hours of sunlight will be between the spring and fall equinox?  It is not the same thing as the solstice but it might do.
Using these calculations, the sloping backyard has about 3 square meters with the correct hours of sunlight.  It is occupied by two 10 meter birch trees and 4 rhododendrons.   Privileged locations.  Can we find a place for all the backyard inhabitants and still squeeze in the apple tree?  Probably not without a significant redesign of the yard.

So I am thinking,  the back yard is like my "self".  This self is a space that  is occupied by a hierarchy of beliefs, ideas and feelings.   Now insert a newcomer, like lets say a new idea that requires a commitment of time and money.  This new commitment will make everything in my self space confusing.  If this insertion happens unexpectedly so that I cannot prepare a plan to readjust the bits in the self,  I will feel threatened and vulnerable.  If I can prune and purge in anticipation of the new idea, I am likely to be less tense.

The yard will be changed even though the sunlight still falls in the same place and the legal boundaries don't move.  So do the garden and yard remain the same?  Or maybe it is a matter of quantity of change and recognition.  Maybe cutting out the rhodos and planting a dwarf apple tree will not make the yard unrecognizable.

Does this mean my sense of self seems to be continuous because the boundaries stay in place even though the hierarchy and the kind of bits have changed irrevocably?  What happens when the edges of my self are threatened?