It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that the Prophet (peace and blessings be upon him) never fasted an entire month except for Ramadan. However, sometimes he would fast with such continuity that we would say, "Now the Prophet (peace and blessings be upon him) will not leave any fast," and sometimes he would break his fasts with such continuity that we would say, "Now the Prophet (peace and blessings be upon him) will not keep any fast."