but never to your actions’ fruits.
Act for the action’s sake.
And do not be attached to inaction.
(Lord Krishna, Bhagavad Gita)
Take any goal of yours, a promotion, a degree, a possession, and you will find that even if you get what you want, the enjoyment will only be temporary and soon enough a voice inside will speak up, "so what's next?, "was that it?", and "if only I also get this next thing I will finally be happy!" There is only one solution to this problem - just as the Bhagavad Gita suggests - aim for the activity per se that gives you meaning and don't worry much about what is in store for you personally.
Accept life as is. It is perfect from a spiritual perspective. Success and failure, progress and set-back are finely attuned to ensure that you learn along the Way to let go of things that no longer serve you. Run after whatever it is that get your juices flowing -that is all you can do anyway- but stand ready to let go when the job is done.
Don't negate your desires but learn that life knows best in providing you with what is yours. Keep the attention on your job, the task at hand, the people you work with and the problems that come your way. When you truly care about what you do and the people you are connected with, your authentic needs will always be fulfilled. And if the ego acts up now and then along the way, then so be it. The sun will shine again even after a little rage, a whiff of depression or a few shattered dreams. The sun always rises the next morning, you must have spotted that pattern by now.
There was a time when I felt that the Bhagavad Gita is a spiritual norm as well - a super-ego so to speak that risks bringing out the demons in you if you repress whatever it is meaningful to you. Today I think of the quoted Gita's verse as an insight instead. We cannot live with or without the ego, with or without the desires and the the aspirations, but we can transcend them. Life does that for you. All you have to do is being mindful and you can discover for yourself that it is only the journey that matters and the people you meet along the Way. Leave your mark for future generations if you wish but know that the "destination" of your journey is every step along the Way.