As principal of a Jewish school in the US, I always felt that once we hit Tu Beshvat, the year is over - there is no time or energy left to do anything except cope with the succession of holidays, get ready for the end of the year, and work on the plans, hiring, etc. for next year.
Haman, according to the Scroll of Esther, was a member of the tribe of Amalek. Thus, we learn the consequences of disregarding the Torah commandment to wipe out the memory of Amalek - as long as they are allowed to continue to exist, they remain a threat, the enemy who for no rational reason constantly plots our destruction. And we read the above passage on the Shabbat before Purim every year,