Here's an interesting experiment you can do around retrospective perception and timing: clap your hands once, listening for the sound of the clap. Notice what it's like to remember the sound of the clap for a minute or so. Now, clap your hands twice, again listening closely and noticing what it's like to remember the sound for a little while. In the second case, is it possible for you to remember the sound of the first clap only, without an echo of the second?