In "Verotchka," what makes Ognev so happy and full of love for people when he leaves Vera's father?

Ognev is happy and full of love for people when he takes leave of Kuznetsov’s family because in the Kuznetsovs he has met good people who have reminded him of the importance of love for others, even when these others are strangers. He thanks Kuznetsov for his “welcome, kindness, affection, and hospitality.” He tells Kuznetsov that his household has been “kind, good-humored, and friendly towards him.” Thoughts of their hospitality overwhelm him with feelings of affection and gratitude towards them, so much so that his “eyes blink” and shoulders shudder. He believes that his statistical work in the district has been successful, largely because of the cooperation, love, and kindness of his host. He even intends to acknowledge his host’s help in the preface of the written work. He thinks that “nothing in life is as precious as people.” He thinks that if everybody was as good as the Kuznetsovs then the world would, indeed, be a “jolly place” to live in.
During his stay in the district, Ognev has been a frequent visitor to the Kuznetsov household. He spends so much time with the family that he naturally becomes well acquainted with Vera Gavrilovna, Kuznetsov’s daughter, and the servants of the house. When he first visits the town, he lodges at Ryabuhin’s inn at a cost of twenty kopeks per day. Later on, he seeks out Kuznetsov, who is the president of the Zemstvo, for assistance with his statistical research work. A friendship then develops between Ognev and the Kuznetsovs so that by the time of his departure, he is almost like a member of the family, and it is therefore with a lot of sadness that he leaves them. It is not surprising that his host’s daughter, Vera, falls in love with him and attempts to talk about her feelings for him towards the end of the story.