英语翻译

英语翻译
A：When I ’m 35 or 36,I'm going to settle down,get married,and have some kids.
B:Oh,you are ,are you?You konw that for a fact?
A:well,it is not a fact--- yet.But really,if you want to succeed,you need to have clear-cut,well-defined goals and aspirations.
是要问‘You know that for a fact？’在此对话中的含义，具体的翻译？其他的意思我都明白。