Context: MC is talking with his friend about the final test before the summer vacation start. His friend is confident that he will pass the exam (with an acceptable grade, enough to pass the red mark :D) and be able to enjoy this summer vacation, since last year he failed and had to participate in the summer supplementary class.
There are a few parts which I don't understand much, so much thanks if anyone can explain their correct meaning to me.
More context below:
大和 (MC's Friend)「はぁ～、今年の夏休みこそは可愛い彼女をゲットして、ウハウハな人生を送りたいもんだな」
MC 「ウハウハねぇ」(my guess: "You want a rich (?) life huh?")
世の中、うまく出来てるというか、何というか、そういうこと言ってる奴に限ってできないんだよな。 (my guess: "In this world/society, I'm sure the people who say things like, how should I put this... "I can do this easy", normally will fail." ??)