Anna,
I wanted to respond to this feeling you describe that certain things are immense and unchangeable -- a frustration which obviously everyone can relate to whether or not they are engaged on ambitous programs of character improvement.

I would say that an important antidote to this feeling is to notice that we change constantly, in deep ways, whether we like it or not. Look at the people you have known for ten years or more -- almost no one is exactly like they were before. They are different in hugely important ways, and not always necessarily for the better: character, tolerance, humilty, arrogance, ambition, dependence, courage, and many others, all serious stuff. Of course, the actual changes in any particular person are perhaps not the ways in which they expected or tried to change. But across the spectrum, more or less all kinds of changes are represented.  Another interesting way to see this is in retrospectives of a particular artist, something which allows you to see a single person's work and thought over the course of forty, fifty, sixty years.

Imagining that your character, with all its flaws, will stand still is like imagining your body will never change. It is affected by every movement you make -- the question is what use you make of this awareness. Mia mentions here post the old chestnut that no one deserves the way they look at twenty, but they are responsible for the way they look at forty. When you repeat old habits, you constantly cut the grooves deeper; when you act differently, you slowly build new muscles. The cumulative effect depends on the strength of the difference. 

There is a certain disservice to ourselves which we do by calling something a "habit" as if it has been fixed once and for all and is not affected by whether or not we continue to entertain it. As long as one is alive, every act is also a choice. Of course, it is no small task to know oneself well enough to get to the root of problems and questions, and to understand precisely what choices are being made --- but the questions are there and cast their shadows whether one's eyes are open or not.

Thanks Molly, I found your description really nice: no moment is empty.

It's funny how life is, isn't it. In novels and movies, everything is very tidy with big changes and dramatic endings. In life of course these things happen, but also day to day existence is much more fluid. You have an argument with someone driving along and you are very upset...you imagine all sorts of apocalyptic endings...but you are there together, and you don't leave, and the mood passes. Or you try every day to do something new or difficult, and it seems that nothing has changed, until suddenly you look back. Whether this is good or not, depends on the situation, of course...

It was a surprising thing for me to understand how in life change is constant and subtle, and because of this difference in scale often slips through people's fingers until they suddenly understand what has happened.  How to be able to use this constant but slight stream of energy to do great things with one's life, that is the question.

Anna: best of luck...

Dear Anna, I think that you got excellent answers and I don’t know if what I’ll say will make any sense, but I will try to compare your question to a musical form. Take the musical form of the Chaconne, the most famous one is BWV 1004 by Bach. The structure of this piece is a theme of 4 measures and its repetition and development through 64 variations. The theme is one’s given character and like a composer, we can choose how we like to develop it and in which directions and how far we would like to change it. Maybe up to the point of not recognizing the original theme- though in the structure and in the harmonic functionality, it is the same root and skeleton. Bach chooses to end Chaconne in the same way he started- with the theme. It reminds me of what people say about old age, that one is somewhere closer to one’s childhood then. Here is a strange CD who specializes in the Chaconne form.