Commenting on the Torah's charge "to be holy, since I the Lord your G-d am holy" (Vayikra, 19:2) the Ramban explains that it is not enough to keep the laws of the Torah. One can do so meticulously and still be a "scoundrel with the permission of the Torah". Torah law gives us a framework for life, but one who so desires can technically stay within that framework while nonetheless violating the basic goals of the Torah. What we often call the spirit of the law—observing the intent of the law and not just its letter—is the mark of holiness.
It is common after a major event to have difficulty getting back into our daily routine. Whether it is a child's wedding, an exotic vacation or a summer at camp, rarely do we feel ready to return to our daily schedule. Surely the excitement of the events surrounding the receiving of the Torah at Sinai would seem to affect our daily activities similarly! The thunder, lightning, and masses of people all gathered to hear the first two commandments directly from G-d would have put one on a spiritual high from which it must have been hard to come down.