...it's what you *don't* do.
Think of all the diets out there that start "tomorrow", the friends that will be called "next week", the vacations/businesses/inventions that will be embarked upon "someday". Sister worlds and lifetimes live alongside our everyday reality, parallel lives that are created and extinguished in intention alone.
This inaction can be as influential as true action is in your life. Good deeds done, or just considered. Creativity acted upon, or dismissed. Connecting with someone, or letting them pass by. It may be easy to gloss over the coulda-woulda-shoulda stuff because we don't see it...but it's there, nonetheless.
When you define yourself only by the things you do, you block some of your own potential. A world of opportunity and choice is available to all of us, but limiting your sense of self to pure action is limiting your sense of wonder about who else you can consciously create yourself to be. Because here's a little tip about your (probable) sense of what you can do: it's largely based on what you've done before. Making new, bigger, brighter, vaster, deeper, simpler, stronger, calmer, earlier, longer seem outside of the sphere of possibility.
Consider what could happen if you brought some of your inaction to action. If you expanded the realm of what's available to you to include the things you have not yet done. Which sister life, which desire or intention, could you bring into your reality?