The Unbearable Lightness of Being
How we cite our quotes:
…seemed in a good mood, even a little boisterous, and tried to make him think she had just happened to drop in, things had just worked out that way: she was in Prague on business, perhaps (at this point she became rather vague) to find a job. (1.4.2)
This is an important parenthetical because it hints that Tereza exists, as the narrator later suggests, to offer up her life to Tomas. He is the sole reason she has returned to Prague, and she is already dependent on him.
Again it occurred to him that Tereza was a child put in a pitch-daubed bulrush basket and sent downstream. He couldn't very well let a basket with a child in it float down a stormy river! If the Pharaoh's daughter hadn't snatched the basket carrying little Moses from the waves, there would have been no Old Testament, no civilization as we now know it! How many ancient myths begin with the rescue of an abandoned child! If Polybus hadn't taken in the young Oedipus, Sophocles wouldn't have written his most beautiful tragedy! (1.4.12)
For Tomas, Tereza means responsibility. Their roles in their relationship are established early on and remain largely unchanged throughout the course of the novel. Years later, Tomas still feels as though he has to take care of Tereza.
For seven years he had lived bound to her, his every step subject to her scrutiny. She might as well have chained iron balls to his ankles. Suddenly his step was much lighter. He soared. He had entered Parmenides' magic field: he was enjoying the sweet lightness of being.
(Did he feel like phoning Sabina in Geneva? Contacting one or another of the women he had met during his several months in Zurich? No, not in the least. Perhaps he sensed that any woman would make his memory of Tereza unbearably painful.) (1.14.7-8)
Again we see that an important idea is tacked on in the parenthetical. Tomas would like to think he's enjoying the sweet lightness of being, but we can already see that there is something unbearable about it. His love for Tereza is weight, but it is the best thing for him.