The Gallagher & Lyle version I found is a bit different:

FIRST LEAVES OF AUTUMN (G&L version)
(Benny Gallagher & Graham Lyle)

As the daylight turns to starlight
And the seasons turn to change,
I get the same old answers
But the questions still remain.

We shared the brief but magic song,
By the first leaves of autumn you were gone.

Not until the rain touched my face,
Not until the first leaf fell from place,
Not until that moment did I see,
Never realized what you meant to me.

From the days you filled with sunlight
And the laughter in your eyes,
To the making of the breaking,
Of the day we said goodbye.

The very words cut to the bone,
By the first leaves of autumn you were gone.

Not until my heart's defence is down,
Not until some old come-all-ye comes round,
Not until that moment do I see
What you meant to me.

Not until the rain touched my face,
Not until the first leaf fell from place,
Not until that moment did I see,
What you meant to me.


from this Gallagher & Lyle recording: https://www.youtube.com/watch?v=cSDuKnXXWKk