Introduction
Without a "good" SME (Subject Matters Expert) stance, Every product is a lesser product then it can be.
This is the bomb I am am dropping here to start with.
There are off course nuances to this statement. I will explain below why this fact is true in my opinion. When you are a SME you care for your product in my opinion. Why would you know so much about the product otherwise? And also have all this information available? I tend to forget things i dont care about.... So i must care about our product.
Finding the nuance within a SME
The struggle is that you need to teach yourself how to react when you are uncertain or wrong. Being stubborn because you are afraid to fail is the wrong take on this stance. You also need to give other people the chance to learn what you might already know. Maybe even some new insights come to the surface! Dictating an answer isn't going to help in accepting your answer until they figure it out themselves. And even more importantly it wont make the team smarter if they dont figure things out themself. The whole team needs to benefit, not just you.
This requires tact and the right moment to step in to certain discussions. You dont want to lead such a discussion but steer it in a natural way to the right direction when it occurs. And do remember there is still always the possibility that you are indeed wrong!
A "good" Subject Matter Expert
Being a SME is bloody darn handy when you have the upper hand on the positives a Subject Matter Expert can bring. That's why this is one the most interesting misunderstood stances of a Product Owner to me. You can be totally in the wrong (misunderstood) as a SME or totally in the right. In a positive way without bothering yourself with everything, every time, again. And that is where you need to find your nuance within your role as a Product Owner with a SME mindset. Also if you know the details of something, also explain the WHY to the team. Keep involving them instead of being Mr Smart-ass.
Limitations
It is all a matter of knowing your limitations and being honest about it. You know a lot but not everything and the world evolves so things might be different nowadays. For me this involves in keeping my mouth shut when i am not sure. And also sometimes i give my take on why we made a choice in the past but i encourage everyone to seek it out in the present day since the problem back then might not be a problem anymore. And you always learn from these things even though the outcome might be the same.
It is good practice if there is somebody to give context to the choices made in the past without steering into a certain direction. I think there is a lot of value in explanations this way.
An analogy
The product we developed as a team started as a child of me. The vision came from me. It took us 2 years before we gave labor. And after that 2 year labor we teamed up to raise our child in the best possible way. This gave a lot of headaches but also brought us so much in learning and adapting to each other. We all started to care for this child.
How can i not pretend to be a SME for such a product? I am the one who started the initial idea. I was there when we gave labor after a 2 year period of close development. I was there all the way through its childhood watching it grow up and get mature. And even though it might be mature now our child still needs guidance and help from time to time. It is still my child after all. That more and more people also started to really care for this child changes nothing to the feeling i have towards our product.
Spread the love for your product across your team. Dont keep it to yourself. Make it better as a team.
Conclusion
I cant help it that i still remember almost every choice we made for our product in the past. And also why we made this choice within our development cycles. I dont particular choose to be that wise guy but this is a topic of interest for me and therefore i remember. I do need to give other people room for their own thoughts tho. So yeah i can relate to, and totally find myself within a Subject Matter Expert to a certain extend.
You do need to know/feel WHEN to step into a discussion. Dont get in a discussion being the wise guy all the time. This all might sound cocky or arrogant. But we all want the same and that is delivering a better product then it already was. If we keep talking in a respectful way without acting as the wise guy we are on the right track as a team.
And again! keep explaining the WHY's and speak your mind. involve your team in decisions and explanations of choices made in the past. You are a team together with all people not just as the PO/SME.
Disclaimer: despite highlighting one stance of the Scrum master stances here. It is a combination of all stances that make you a better Product Owner. This is just one stance that interests me for being a misunderstood stance (and for a good reason). Without a clear Vision and "being" all the other stances you are going to have a hard time as a Product Owner.