Do you have to be happy in adar? What is included in “Simcha” when Adar comes?
The concept of simcha in Adar is generally understood to mean a spiritual/emotional state, rather than actually doing physical deeds that induce joy. We do not find an instruction to drink, or to feast and be merry, in days of Adar more than during the rest of the year. The expression of joy in Adar is therefore a little vague, and one should take greater joy from the everyday things that one does (divrei reshus), and focus on the special joy of the build-up to Purim. Rabbi Chaim Shmuelevitz (Rosh Yeshiva of Mir) used to speak of dedicating extra hours to learn Torah (and used to do so himself), thereby “adding joy” to the month!
Sources: See Nimmukei Orach Chaim 686.