After Lazarus died, many people, including Mary and Martha, were mourning for Lazarus. When Jesus came to visit the mourners, he too "was troubled" (11:33). Jesus felt troubled because Lazarus died, and Jesus cared for Lazarus (as well as Mary, Martha, and pretty much the entire world).
Eventually, after a request, people showed Jesus where Lazarus was buried. In response, Jesus wept (11:35). John 11:35 is one of the shortest verses in the Bible (and one of the easiest to remember, too) -- and as short verses go straight to the point, this verse emphasizes Jesus's heart for Lazarus who has died.
Even though Jesus had a plan to reveal himself to strengthen the faith of the disciples and some of the mourners, Jesus does not take joy in people living through horrible scenarios; rather, Jesus wept because of his care towards people like Martha, Mary, and Lazarus.