Re: YAY! -- part 1
I'm so, SO glad you like this! I got really worried when there was no comment from you, and eventually took to clicking on your journal, and then you had the post saying you would comment the next day, and then didn't -- and although I knew logically that your RL issues had probably continued to interfere (after all, it's a long story), I couldn't help fretting while I waited.
The Can't Tell jinx is based on something that was done in my grade school, and as soon as I realized that the word was "Please" (and I swear that was Minerva's choice!), I knew when he'd say it. Poor Harry!
When I was writing this, it occurred to me that the de-aging fic is often talked about as if it's just a way to make characters more physically attractive, but I was showing that the appeal (for me, anyway!) was more complicated than that. I'm really glad you mentioned "amnesia" so close to "Snape is a teenager" in your request, because I don't think I would ever have come up with this idea without that.
I also had a lot of fun with Albus Severus, whom I've never written before. I had to restrain myself, really -- it was tempting to write more of him than was needed.