All users of complex software make decisions that they may later wish to change. Many computer systems have tools to support this need for revision, such as the undo command. However, the common history tools (like undo) do not support exploratory, epistemic interaction well. And there are common, non-specialized tasks that are difficult in common computer systems, but would be much easier with improved support for managing interaction history. Desktop computing environments have well-established norms for how undo works, but there is room to explore this in newer computing environments, such as the Web and surface computing, as their design culture has not stabilized to the same extent. We argue that history tracking needs to be more accessible to users.