It is not a question of being attached to the present moment. You ARE the present moment. This moment is all there is. The past is your memory. The future is your imagination.
Therefore being in the moment and accepting the emotions that are present is not a form of attachment, it is a way of coming to terms with reality on reality’s own terms as opposed to your own.
Attachment is the desire to freeze things as they are and keep them that way. Detachment is the awareness that all things change, all things come and go. Nothing is yours, not even your body.
Choices are indeed ego-oriented because choice implies preference. Any choice you can make will only have relevance to your ego, to your concept of separate existence. When you understand through experience that you are inseparable from the world you experience, what choice is there to make? You simply flow."