Just a cute story:
Someone once asked the Vilna Goan which is the best mussar sefer. He pointed the the wall in the back of the room. So the person went to the back, but the only seforim on the shelf were meforshim on the gemorah, some gemorahs, etc, but no musser sefer. So he tells the VG there aren’t any mussar seforim here on the shelf!? The Vilna Goan smiles and points up, just above the seforim shrank where a clock was hanging on the wall. “That clock is the bestmussar sefer!”
🙂