This will be the tease for a story I'm working on. I need feed back: thoughts, corrections, suggestions, what you like, what you don't like. All greatly appreciated.

There will be a time when you look back on you life. On everything you've even done, thought, or chose. What you've said and how you've acted. On all the people who have been in your life-- stranger or not-- and what they've done in your life. In their life. On how the world was then, and on the environment around you. Of how you reacted to things. To anything. To everything. To the smallest detail. You will look back. And Judge.
You will realize the person you've been-- and the person you want to become. For in this moment, you will have discovered things about yourself that you have never known-- even never thought possible of yourself.
You will have discovered who you are, and what makes you unique. You will have to make choices in that moment. Choices with impacts. Choices about youself. Choices that might effect the world over, or maybe someone's well-being. Choices that you will have to live with for the rest of your lives.
I only hope that those choices don't come with regrets.

Well, it sounds good so far, but it almost sounds like a self-help book.
It's a little personal, maybe start of the first few lines addressing the reader, then switch to a character's perspective?

If you provided a little more context for the teaser: vague rundown of the plotline, character names and/or roles? It would be more helpful for use to help you :)

It sounds more like part of a prologue, though perhaps that was your intent. Keeping what you've got and relating it to a specific plot - just enough to give an idea of the genre of this story - would make it really good. The teaser makes it hard to tell if it'll be a story a person might like, because it does seem like one of those self-help things. This isn't a BAD thing, per se, but if it's not just about a person realizing and identifying/correcting the mistakes they've made in the past, you want to clarify that better so people know.

Generally though, I think it's pretty good :)

I have to concur with the others. It does read more like a prologue than a teaser. I feel a teaser should, as the others have mentioned, give you an idea of the characters, plot and overall genre of the story. Without that type of information it's hard to make an assessment of the story as to whether one would like to read more. Your writing style and sense of suspense felt good to me though. I'd be interested in reading a bit more to find out what you have in store. :)