משנכנס אדר מרבין בשמחה
When Adar comes in, we add in simcha – happiness.
The Talmidim of Yeshiva of Staten Island asked Rav Moshe Feinstein ZY”A, how should they fulfill this Halacha. Rav Moshe answered them that they should learn more Torah, and they should drink a little wine every day.
As I heard from my Rebbe, Rav Refoel Green ZY”A
אוהבי אחי תאמינו לי ...
My beloved ones, my brothers believe me, it is complete in all the Seforim, that what was needed for the earlier Tzadikim to attain in many days and months, it is possible presently to be מתקן in one hour.
Sefer Bais Aharon ד"ה בפזמון מובא בספר אז תתחזק דף נ"ב
It is only possible to pass through this world, with the influence of Simcha - happiness.
Rav Avrohom – The Sabah Kadisha of Slonim ZY”A
Seforim quote, when Yaakov Avienu escaped from Lovon, it was Amoleik who notified Lovon. And so it is in every generation.
Sefer Beis Aharon - Karlin
Alter Boyaner Chassidim would wish each other “Simcha ohn Chizuk” (happiness without the need of uplifting).
As heard from Horav Binyomin Adler Shlit”a of Yerushalayim