Lady Gaga's surprise appearance at U2's Vegas show looked like an all-time thrill

I have tried not to be jealous of my friend Lolo who was in Vegas for the U2 show a couple of weeks ago because while I’m not as out-of-her-mind obsessed about U2 as she is, I mean, I was around during the rise of U2. I was around in the time of The Joshua Tree and “With our Without You” was the sou...