A milestone age can arrive before the feeling everyone associates with it.

Numbers and inner states run on separate clocks. Thirty, forty, sixty arrive on the correct day whether or not you have acquired the settledness, authority or wisdom that everyone seems to have agreed comes with them. The result is a private suspicion that you have missed a step other people managed. Almost nobody feels the way their age is supposed to feel, and almost everybody assumes they are the exception.

If a birthday like this is near, drop the comparison to the script. Ask instead what you actually have now that you did not have at the last one.