Rashi explains that the Gemara does not mean that Aba Binyamin (not Aba Shaul) was pained, but rather that he was particularly careful about two things. He was careful, when he arose in the morning, not to work or even learn before he had recited the Shema and prayed. He was also careful to place his bed facing north to south, since the Shechinah is situated either in the east or in the west.

The reason that he mentioned specifically these two issues was presumably because he saw that other people were lax regarding them, or because it was not always easy for him to fulfill them.

Wishing you a good Chodesh,

Eliezer Chrysler