Yes, Manifestation is a real thing but there  is an extremely important distinction to be made first.

There is a completely external reality from our internal reality. Manifestation is about bring that internal reality into an external one. But thoughts do not directly change reality and what you imagine doesn’t become real. This kind of magic does not happen the way you think and nothing appears from nowhere. What happens is your formulate a positive outlook on life and self, that positivity becomes a gravitational pull that invites, people and things into your life; that is manifestation.

Furthermore, much of the reality we experience is internal where reality itself is the manifestation. The way you think determines your reality and what you imagine is an extension of your understanding, which in turn shapes your experiences and your perception.
Both of the above are true, but not to be confused.

Perception is defined as the ability to see, hear, or become aware of something through the senses. Thus, perception is fully generated by our brains. So by controlling our perception by way of our brain, there are many ways in which we can alter our experience. Furthermore, interpretations are a product of our understanding and improving our understanding will alter our experience also.

For example, falling and breaking a leg is real and something that happens regardless of thought. But our experience is a product of what we make of it. Some may curse the gods for their misfortune. Others may interpret it as a sign and some may not think much of it, except for it being a hassle and a setback in their lives.

The world we experience is a frame within which we place ourselves comfortably. Our biological survival instincts necessitates that we understand how to survive, and that we adapt to our environment. This is what intelligence is, the ability to navigate our environment effectively. Being as advanced as we are, the result is a world of experiences and memories. These are natural, but they are not equal to the external reality. External reality can be similar or extremely different from our perception and lived experiences.

 We then share our realities and find common ground, and assume our experiences are more or less the same. But each and every one of us lives our own paradigm, and that paradigm is intimately related to who we tell ourselves we are, and how we explain what happened.

What we live is a narrative more than it is an experience. The past is what we tell ourselves happened. The present is what is about to become more of that past.

What does this all mean?

This means we have far greater control over reality than we are predisposed to believe. There is just as much reality inside us, than there is outside us. Most of reality is an extension of ourselves and we can bend some of this reality with our willpower.

By changing who we are, we change the frame that shapes our experiences. Wishing and hoping is evidence of that first step.

When wishes are granted, all it really means is they were very real possibilities to begin with.

Glattfelder J.B. (2019) The Consciousness of Reality. In: Information—Consciousness—Reality. The Frontiers Collection. Springer, Cham.