There are two Parshiot in the Torah that contain the Ten Commandments, Yitro and Vaetchanan. The word Zachor, remember, appears in Parshat Yitro, describing how one should remember the Shabbat. Shamor, safeguard is written in Vaetchanan. Rashi tells us that Hashem said both words simultaneously, when He gave the Ten Commandments. This would mean that both commandments are equal parts of Shabbat. The Ramban resolves that the word Zachor was inscribed on both the first and second set of tablets, and Moshe explained the negative commandment Shamor on his own. He adds that, in the Kabbalistic sense, when Hashem told the Jews the commandment of Shabbat, Moshe heard Zachor, and the nation heard Shamor. At the highest spiritual level, Moshe's level, there is a tremendous positive phenomenon involved in the Shabbat. One who understands this positive level finds it impossible to desecrate. However, the rest of the nation did not comprehend the elevated nature of the Shabbat. They had to be told that it is forbidden to desecrate the sacred day. When they heard the Ten Commandments, they only understood the negative commandment Shamor.
Let us all try to understand the true depth and beauty of Shabbat so that desecrating it will not be an option, but an impossibility.