Everything you experience is That. To go looking for an experience of the Self has to be self defeating because you cannot find what you already are. You cannot experience anything that is not the Self, so where can you go to find it? What is really required is recognition, often called realization.
Realization is an understanding, and the beauty of this understanding, is that you don't have to be experiencing oneness or bliss to know who you are. This is why Vedanta is considered knowledge, and why it is the knowledge that ends the search.
Of course, if you want to pursue experience, you can find ones that are blissful and unitary. Experiences of mystical union, however short, can have profound effects. There is probably nothing that feels better than the ecstasy of the experience of oneness. These experiences, however wonderful, may not lead to understanding.
To chase after the experience of oneness can be frustrating, because, as an experience, it doesn't last. And if you make the error that the experience of oneness is enlightenment, you will set yourself up for a lifetime of searching, because no experience lasts.
Experiences of oneness, bliss, and ecstasy can, however, point to understanding. They become part of your understanding. They can contribute to the knowledge you need to understand who you are. It is a boon to experience oneness, as opposed to the limited experience we typically have.
When the experience of oneness is gone, understanding is what keeps you on an even keel. What really helps is firm conviction and sureness as to our real being. The knowledge of our actual beingness as Awareness. One with all that is.
Knowing oneself as Awareness keeps one from continually looking for a particular experience. With understanding, one doesn't mind the particular experiences of a limited human form. They are just an experience, not who you are.
Awareness sees through many forms, and experiences what is particular to that form. Awareness, as John Doe, picks up the qualities and positions that make up John Doe. This is experience, and it may feel limited, but it is not who you are.
To get beyond limitation requires understanding. It requires an understanding that is deep and broad, seeing that the whole world is but a myriad of local focal points superimposed on oneness. Only understanding will take you beyond experience.
The understanding is twofold. The first is to see that everything is a form of the One. The second is to see that you are That One. Seeing this is understanding.