Inconsistencies are found in the subjectivity of the matters being discussed. If you think happiness and a life of meaning can be intertwined, please explain why. I'm not opposed to that view point. In fact, I'd like to learn how people can accomplish both at the same time.
When I say inconsistancy I mean logical fallacy, so it is a logical fallacy to say you must not focus on the future or past, but instead take you're current situation and better it.
But anyway let me try and take a stab at why happiness and a life of meaning can be intertwined.
One it depends what you mean by hapiness, I'd assume its a feeling of contentment and joy, a mix of the 2.
When you dedicate your life to some higher meaning, you have the feeling of accomplishment, you have the feeling of joy of creativity, you get rid of egoism (which I believe is a source of unhappiness, because selfishness will lead one to want to continue to aquire hedonistic pleasures for ones self, hedonistic in the technical term, which one will never achieve enough of, and will always be lacking), I think dedicating yourself to something like service to others, is a good way to achieve happiness, although happiness is not the goal.
When you are not focused on your own personal desires but instead focus on a higher project, you kind of attain happiness as a side, through the feeling of accomplishment, a feeling of union with others and a cause, and you're letting go of yourself, in the sense that you stop worrying about yourself, your own pleasures and isntead worry about the larger thing and more about what you try and do for the larger thing, having a good concience in a way, like "I did all I could for this thing which is bigger than me."
I take the view Jesus did "there is more happiness in giving than recieving," that entails a larger purpose and meaning.
I'm not going to claim that I have the answer (again), but I take the view that letting go of egoism, dedicating yourself to a higher meaning, and a life of love, brotherhood/sisterhood of somesort i.e. community and service is the way to happiness.
I think the number one mistake is thinking the way to happiness is to chase after the feeling of happiness directly, through things like pleasures or the such.