I stole a toy of my nephew and...uhm, what I was writing? Ah, ok. Well, the main target of Kierkegaard's writings was the idealist philosophical system of Hegel which, he thought, ignored or excluded the inner subjective life of living human beings. Kierkegaard, conversely, held that "truth is subjectivity", arguing that what is most important to an actual human being are questions dealing with an individual's inner relationship to existence. In particular, Kierkegaard, a Christian, believed that the truth of religious faith was a subjective question, and one to be wrestled with passionately.
Although Kierkegaard and Nietzsche were among his influences, the extent to which the German philosopher Martin Heidegger should be considered an existentialist is debatable.
So it's ok, and bella lì.