Being Happy with Your Portion in Ruchniyus

Chazal (Avos 4:1) say, בחלקו השמח עשיר איזהו, "Who is happy? It is the person who is happy with his portion." The holy sefarim (Sfas Emes, Tiferes Shlomo [Ki Savo ושמחת ה"ד], and in Menuchah v'Kedushah [written by a student of Reb Chaim Vital, in the section Shaar HaTorah vol.2 23 quoting the Vilna Gaon zt'l]) say that also in ruchniyus matters one should be בחלקו שמח, happy with his portion. One should always strive for more, for better, but simultaneously, one should be happy with his accomplishments, with whatever good deeds he succeeds in doing.