Continuing on the theme of "Awe and Joy" as it relates to today's daf, I just wanted to highlight an amazingly powerful explanation of the concept given by R' Avraham Eliyahu Kaplan.
I first heard this explanation from my Rosh Yeshiva in High School more than 20 years ago, and it has stayed with me ever since (even more so after becoming a father, as will soon become clear).
[If you are capable and have the time, I highly recommend reading R' Kaplan's entire essay "Be-Ikvus Ha-Yirah" in Hebrew. I personally revisit it at least once a year before Rosh Hashana.]
"Yir'ah is not anguish, not pain, not bitter anxiety. To what may yir'ah be likened? To the tremor of fear which a father feels when his beloved young son rides his shoulders as he dances with him and rejoices before him, taking care that he not fall off. Here there is joy that is incomparable, pleasure that is incomparable. And the fear tied up with them is pleasant too. It does not impede the freedom of dance... It passes through them like a spinal column that straightens and strengthens. And it envelops them like a modest frame that lends grace and pleasantness... It is clear to the father that his son is riding securely upon him and will not fall back, for he constantly remembers him, not for a moment does he forget him. His son's every movement, even the smallest, he feels, and he ensures that his son will not sway from his place, nor incline sideways - his heart is, therefore, sure, and he dances and rejoices. If a person is sure that the "bundle" of his life's meaning is safely held high by the shoulders of his awareness, he knows that this bundle will not fall backwards, he will not forget it for a moment, he will remember it constantly, with yir'ah he will safe keep it. If every moment he checks it - then his heart is confident, and he dances and rejoices..."
(Translation taken from R' Yosef Gavriel Bechhofer here: http://www.aishdas.org/rygb/raek.htm)
I think any added words on my part would be superfluous.