After the miraculous event of קריעת ים סוף, the Torah states that the people declared "זה קלי ואנוהו," this is my G-d and I will glorify Him )שמות ט"ו:ב'(. The Midrash says based on this Posuk that the people actually "saw" Hashem, and that even the lowliest of maidservants saw at the time of the miracle of the splitting of the Sea more than Yechezkel the prophet ever saw. This means that their understanding of Hahsem was at a very high level.
Rabbi Chaim Shmuelevitz, commenting on this Midrash, said that ultimately, the maidservants, despite this extraordinary event, remained maidservants and didn't achieve the greatness that Yechezkel achieved. A person can live through the greatest experience possible in the world, but if that doesn't lead him to elevate his behavior and to change his overall character for the better permanently, then it is not that significant an experience in the long run. The real challenge is to react to an experience that raises one to a high level by maintaining that high level.
Rabbi Shmuelevitz added that the same idea is seen a few Pesukim later where the Torah states that all the nations trembled when they heard of the splitting of the Sea (שם פסוק י"ד). They trembled then, but that incident did not change their lives. It was only a special feeling that they felt for a few moments, but it didn't cause them to make any major changes in their lives. The goal of Mussar, and really of all Torah learning, is that the person should internalize his insight and awareness and make them become a part of him, so that his whole behavior will be improved. Whenever one feels spiritually elevated because of a new understanding or appreciation, one must make sure to take some positive action in order to ensure that he will come away with something more than just a vague feeling which will eventually fade into memory.