Running several applications on a small, mobile device requires their constant adjustment to changing environments, user preferences, and resources. The decision upon this adjustment has to regard various factors of which the optimality of the result is only one: Further non-functional aspects including user distraction and the smoothness of operation have to be taken into account, too. This paper explains various events causing adaptation and details several non-functional aspects to be considered. It then presents Serene Greedy, a pragmatic approach for deciding upon adaptation and non-adaptation of simultaneously running applications in resource constrained, mobile settings. Finally, this paper discusses Serene Greedy by comparing it against other adaptation reasoning techniques for performance and the mentioned non-functional properties.