Portion of Bo - what is REALLY the beginning?

.The portion says "This (Passover Season)  is the HEAD of the Months"
and right away says "This is the FIRST of the months."
In Hebrew head is "Rosh" and first is "Rishon" - both words from the same root!
So what does the Torah teach us that the "Head Month" is the "First Month"?
In the Kabalah it explains that there is "chesed" - kindness from Hashem
and there is "Rav Chesed" - the GREATEST or the ESSENCE of kindness.
It explains that Moshe was the first to prove the KINDNESS of the Almighty
but (in the Purim story) Mordechai proved the ESSENCE of G-d's kindness
So I think that the HEAD month - Nisan - from the Exodus from Egypt
taught us the Almighty's kindness-
but RISHON - calling it  the FIRST MONTH
the START of it ALL -
we would only learn as the People of Israel grow and develop - and LOOK BACK
and we learn TO THIS VERY DAY- every day more and more - that
the kindness of leaving Egypt and all our troubles -
follows us - the People of Israel -
into every land and into every time.
With Blessings of Shabbat and Health and seeing we are leaving all troubles behind -
Rabbi Andy Eichenholz