I tend to be overly positive when discussing new ideas, my take is that when you are discussing change, you should always start from a position of anything is possible. It's true that you don't always get to do everything perfectly or as you'd like, however, why constrain something at the outset?
I do think about the details and challenges and get that some things aren't possible or there will be cultural or technical challenges with everything... however, there is a way to frame things that add to conversations rather than detracting from them.
There have been so many conversations / meetings that I've been in where people are quick to bring up the why something won't work or what the challenges will be and it frustrates me to no end.
My new question to them is simple: how would you solve it if you had to?
It's simple to point out why something won't work or how hard something is going to be... it's something totally different to figure out how to make stuff work, and trust me, there is always a way. Of course you can't do everything and some stuff has to be out of scope, however, instead of bringing up something negative why not just create a list of things to research (parking lot items)?
How do you keep conversations framed in constructive terms?