One of the harder things to learn in software development is the skill of letting go. We spend hours and hours (and days, weeks, or even years) working on a thing, and we naturally grow attached to it, especially when it is something we are passionate about.
This is all good to the extent that we often do our best work when we are emotionally invested in it. But it does have a downside, which is that we can be so close to it that this prevents us from seeing its warts. It can also cause us to be protective like the proverbial mother bear with her cubs--to keep everyone else at a distance.
Both of these ultimately lead to having a worse end solution than is possible when we are open to criticism and open to letting others take our work in new and, sometimes, different directions that we personally would not have taken.
The first aspect--open to criticism--is especially important during the early, formative stages of developing an idea into the artifact. A key way to help be open to such criticism is to, ourselves, try to come up with several significantly different approaches to solving what we are trying to solve, and presenting all of them as impartially as we can to others for their review and criticism. The simple act of creating such multiple alternatives weans us from our babies, so we are more able to accept constructive criticism. We then can synthesize the best of all this into a better solution. This is the essence of the Design process.
The second aspect is important during the main effort to develop the idea into a concrete thing. Especially on larger ideas, it is easy to become a roadblock to needed progress because we think only we have the ability to properly drive to a successful outcome. It is important to remain involved, but it is also important to create space for other persons to carve out some parts of the effort and to really own those parts for themselves. Just as we do our best work when we are invested and have a sense of ownership, so do others. And being overbearing, even with good intent, can sap others' energy and passion.
It is similarly important to really be able to let go, when we find ourselves needing to move on to other things. When we no longer are as involved or as invested but, because it was "our baby," we sometimes feel the need to retain that protective mother bear stance. That, too, can kill the healthy evolution and ongoing success. This is the final step, in a sense, of making space for others to thrive and contribute. And it is key. That point almost inevitably will come, and we have to be able and willing to take that step of "faith" and entrust our baby to others.