Look and See
Some people think that if they always assume the best in people and their intentions, that's "being positive," but it's really not.
Now, it's not good to assume the worst, either…
Just don't assume anything.
As. Observe. Ask again. Observe again.
If you only assume the best, you will eventually be disappointed when you realize that they are not who they never were.
If you ask and observe, you can truly get to know them, and choose to accept them as they really are, with no false pedestals and no expectations of perfection.
That's "being positive."
In fact, that's love.