From an email

If you put a buzzard in a pen that is 6 feet by 8 feet and is entirely
open at the top, the bird, in spite of its ability to fly, will be an
absolute prisoner. The reason is that a buzzard always begins a
flight from the ground with a run of 10 to 12 feet. Without space to
run, as is its habit, it will not even attempt to fly, but will remain
a prisoner for life in a small jail with no top.

BAT

The ordinary bat that flies around at night, a remarkably nimble
creature in the air, cannot take off from a level place If it is
placed on the floor or flat ground, all it can do is shuffle about
helplessly and, no doubt, painfully, until it reaches some slight
elevation from which it can throw itself into the air.

Then, at once, it takes off like a flash.

BUMBLEBEE

A bumblebee, if dropped into an open tumbler, will be there until it
dies, unless it is taken out. It never sees the means of escape at the
top, but persists in trying to find some way out through the sides
near the bottom. It will seek a way where none exists, until it
completely destroys itself.

PEOPLE

In many ways, we are like the buzzard, the bat, and the bumblebee. We
struggle about with all our problems and frustrations, never realizing
that all we have to do is look up.

Sorrow looks back,
Worry looks around,
But faith looks up