From chapter 5 of To Kill a Mockingbird by Harper Lee:
We saw Uncle Jack every Christmas, and every Christmas he yelled across the street for Miss Maudie to come marry him. Miss Maudie would yell back, ’Call a little louder, Jack Finch, and they’ll hear you at the post office, I haven’t heard you yet!’ Jem and I thought this is a strange way to ask for a lady’s hand in marriage, but then Uncle Jack was rather strange. He said he trying to get Miss Maudie’s goat, that he had been trying unsuccessfully for forty years, that he was the last person in the world Miss Maudie would think about marrying but the first person she thought about teasing, and the best defence to her was spirited offence, all of which we understood clearly.
Please explain the lines in bold.
Also, why did Miss Maudie compare Uncle Jack’s playful nature with Jem’s ideas about Boo Radley ("He gets more like Jack Finch every day")?