The Email That Changed Everything

So here's the thing: I've worked at this software company for five years now. I started as a junior engineer and through hard work, dedication to learning new technologies, and a bit of luck with hiring cycles, I'm now a lead developer on one of our biggest projects. It's been an exciting journey and I genuinely enjoy my job and the people I work with. Recently though, something has felt off in my day-to-day. There’s this newer team member who joined about six months ago, a very skilled junior engineer named Lisa. We've had some great interactions; she often approaches me for advice on certain technical aspects of our project, which I appreciate and feel good about helping out. But there's also been some tension, Lisa is incredibly talented, perhaps more than any junior should be at this stage. Last week, we were assigned a new task to optimize an old piece of software that has been causing us issues for months now. The deadline was tight but I knew it would be a great opportunity for Lisa to showcase her skills and potentially shine in a high-pressure situation, which could help her career progress here at the company. So I delegated the responsibility to her. Then, a funny thing happened: As we approached the deadline, she didn't just complete the task but made significant improvements that were beyond what was expected. This left me feeling both proud of my decision and... well, a bit threatened. It's not like anyone can replace me as lead developer, but I started to question my own skill set and contributions. To be honest, this realization scared me. Instead of congratulating her publicly, or even privately via Slack message, I wrote an email stating that some aspects of the improvement were 'overkill' and 'wasted effort.' It wasn't exactly malicious, I don't think anyone else read it, but I can’t help but feel guilty about my motivations for sending it. Now every time Lisa asks me a question or comes to me with ideas, there’s this little voice in my head saying she’s trying to replace me. And honestly, I hate that part of myself. Why am I feeling threatened by someone who is clearly doing great work? Am I really the asshole here for not being supportive?