We all have desires, ambitions, things we need and want. That seems to be our nature. Buddhist thought, at least at its distilled nondual form, neither recommends nor avoids these.
When we want or need something, our energy is naturally channeled to achieving it. We tend to think, speak and act so as to get what we need. It is natural. However, none of this guarantees that what we want will actually come about. This world seems to be beyond our understanding and many factors influence the future in addition to our own desires and actions. Most of these factors are neither under your control and you may not even know they exist. So the actual future remains unknown, even while you are acting to achieve something.
The peace it seems the Buddha pointed to is no more than appreciating this deeply. Then your peace of mind is less dependent, ultimately independent, of whether you do or do not get what you want. There are no disappointments in life. There is no feeling of having done the wrong thing, of anger or loss of control and all the other so-called negative emotions.
All that remains is deep serenity and the total happiness that follows naturally from the absence of anything that can disturb you. You can equally call it love, or compassion, or kindness. A natural, gentle being what and who you are in the world as it is. After all, there is actually nothing else.
This may be at the heart of nondual Buddhist understanding.