I wish I could remember that first day

Christina Rossetti, from Monna Innominata. "Did one but know", indeed!

Era già l'ora che volge il desio. - Dante
Ricorro al tempo ch' io vi vidi prima. - Petrarca

I wish I could remember that first day,
First hour, first moment of your meeting me,
If bright or dim the season, it might be
Summer or winter for aught I can say;
So unrecorded did it slip away,
So blind was I to see and to foresee,
So dull to mark the budding of my tree
That would not blossom yet for many a May.
If only I could recollect it, such
A day of days! I let it come and go
As traceless as a thaw of bygone snow;
It seem'd to mean so little, meant so much;
If only now I could recall that touch,
First touch of hand in hand - Did one but know!