Prayer is considered avoda she-ba-lev (worship of the heart); therefore its essence is dependent upon kavana.
This is what the pious and people of deeds would do: They would meditate and concentrate on their prayers until all physicality fell away and the power of the mind would gain strength, to the point that they were on the verge of prophecy. If another thought would intrude on their prayer, they would be still until that thought passes” (SA 98:1).
There are two kinds of kavana in prayer: One is a general kavana, where the person praying stands before the Supreme King of kings filled with awe and love; the second is a specific kavana – concentrating on the words she utters.
People are innately different from one another. Some can focus effortlessly, and though they repeat the same words every day, it is easy for them to follow each word and mean them. Others naturally find it difficult to concentrate, and the more familiar a subject is to them, the harder it is for them to focus on it. Try as they might to have kavana, their thoughts wander from one matter to the next. Despite great effort to have kavana while reciting Avot (the first berakha of Shemoneh Esrei), their minds are flying away, and suddenly they find themselves saying Selaĥ Lanu (the seventh berakha). They attempt to refocus, but their minds wander off again. Before they know it, they are already bowing for Modim (the seventeenth berakha).
Even in the time of the Talmud there were Amora’im who lamented the difficulty of focusing during prayer. Y. Berakhot 2:4 records that R. Ĥiya says that he was never able to have kavana throughout his entire prayer. Once, when he tried to concentrate for the duration of his prayer, he began wondering, right in the middle, whether Minister A or Minister B is more important in the king’s eyes. Shmuel said, “I counted newly hatched chicks while I was praying.” R. Bon bar Ĥiya said: “While I was praying I counted the rows of the building.” R. Matania said, “I am grateful for my head, for even when I am not paying attention to what I am saying, it knows by itself to bow at Modim.” The statements of these leading Amora’im teach us that it is difficult to have kavana from the beginning of the prayer service until the end. Even though we must try as hard as we can to concentrate, one should not lose heart when she does not focus properly. Even one who daydreamt throughout most of her prayer should not despair; rather, she should strive to have kavana while reciting the remaining berakhot.
One should not say, “If I do not have kavana, perhaps it is better not to pray.” Rather, the very fact that she stood before God in prayer expresses something very profound – her sincere desire to connect to God and to pray before Him. Every person is measured according to her nature, and at times, someone who finds it difficult to concentrate, yet struggles and succeeds in having kavana for a number of blessings, is more praiseworthy than someone for whom focus comes easily through the entire prayer service. Moreover, people who find it easy to concentrate on the routine prayers generally pray without any particular passion, even on special occasions, or when a tragedy befalls them. However, those individuals who find it difficult to concentrate on the routine words usually succeed in attaining higher levels of kavana in exceptional circumstances.
It is said in the name of Arizal that kavana is like the wings upon which prayer soars heavenward and is accepted. When one prays without kavana, her prayer lacks the wings with which to ascend, and so it waits until she utters one prayer with kavana, whereupon all the prayers that she recited without kavana ascend to God together with the prayer that achieved kavana. The reason for this is clear: The very fact that she chose to pray demonstrates that she wants to connect to God, to praise Him, and ask Him for her needs. She simply failed to have kavana. However, the moment she succeeds in having kavana, she opens the gate for all her prayers to ascend.
In practice, one who has kavana during the first berakha of the Shemoneh Esrei fulfills her obligation, even if she did not have kavana for the rest of the prayer (SA 63:4, 101:1; below, 12:8).