Wait..what happened?

It's weird now that in idle times when I am doing something mundane like drying my hair, thoughts of successes or failures with students in the past week, or lesson plan ideas creep into my mind. So weird, so very very strange.
Anyway, as I was doing just that tonight, my mind wandered to a student in my class that I have seen a transformation with in the last week. So first the back story:
My master teacher for this group was, how shall we say, quite permissive last semester. The students in that class all passed, most with As, but for very little work or instruction. There was a bit of resistance to me from them for this reason. I was making them read and write and work (I know, I'm a monster). One student in paticular REALLY did not take well to this, and slowly but surely, week by week, I found that he was slipping away. He showed up, stayed conscious, but that was about it. This was completely out of character for him. I was planning to talk to him, what to say and when, when all of a sudden he stopped showing up to my class. He ditched for a solid three days right after taking a test on the book.
He had aced it. He was not only spot on with his answers, but thoughtful with them. This kid had all the tools to succeed, and yet somehow I was failing him. When he came back, I was planning to talk to him after class, but in the meantime I was passing out grades. When I put the test on his desk, face down, I saw him out of the corner of my eye roll his eyes. When he picked up the test and his mind processed the fat A+ on the page, his entire demeanor changed. I have never seen anything like it. He started showing it off to his friends, and for the rest of the period he was completely engaged, participating readily and thoughtfully.
After class, he came up to me inquiring where this had put his grade in the class. I gave him the grade, pointing to all the work he had blown off beforehand bringing his average down. He inquired what he could do to make it up, and I worked with him on that. As our little confrence was reaching it's close, I said "You have what it takes to be successful in this class. You just have to show up and show me more of what I saw today." He nodded really seriously, and then said "Thanks for your help" and was off.
I can't really explain even now what happened there. The only way I can really account for it, is that sometimes we need those little proofs of success to validate the point of it all. I think this student was so afraid of failing before he even tried, that he just withdrew completely. That test then came along, giving just a little bit of validation and the encouragement to press on. I'm sure that there is even more to it than that, so if anyone has any insights, please share.
I just couldn't help but be reminded of this time in the fifth grade when I had to tag along with my mom to my brothers back to school night. A large group of adults, including his third grade teacher were talking, and for some reason someone ended up asking me "what do you want to be when you grow up?"
I excitedly recited "A supreme court justice!" (I was 10, why did I even know what that was?) I remember all the adults laughing and the third grade teacher saying
"Oh dear, you've probably already done something in your life to screw up your chances of that"
I never ever want to be a person that makes someone else feel that way.