I've been the sole developer of a niche product for my company for nearly 6 years. I've grown quite attached to the project and I enjoy working on it. However, it was the decision of management to take the project out of my hands and move it under the wings of another team.

Unfortunately, I'm having a hard time letting go of the project. I'm sad to see it leave my hands since I've put so much time into it and enjoyed working on it, but it also allows me to work on new things. I've even caught myself being a bit hostile to the other team, which is poor on my part.

How can I convince myself to just let it go?