In a learning sense, I've found that reflection forces students to think back to what actually stuck with them. Maybe nothing did, which tells the student they should probably pay more attention to what's going on, or maybe something groundbreaking stuck with them. I know I've had a couple of both moments over the past 8 weeks. I've found that being able to think back on what i've done and experienced gives that experience another level of learning, and stays with the student longer.
In a personal sense, I've had a big helping of humble pie. I really don't know how to be a highly effective teacher... yet. I have had superb teachers model what this looks like, but I haven't done it for myself. I am not going to get better if I don't reflect upon what I do and how to improve. Albert Einstein said "the definition of insanity is doing the same thing over and over again, and expecting a different result." Without reflection, I may indeed go insane. My effective teaching skills will grow as I go through practicum, and they will stay with me longer and be most meaningful if I take the time to reflect on what goes well and why along with what goes poorly and why. (I anticipate answering the latter part most often.)
I've come to realize that reflection is not always fluffy, "how did this make you feel" stuff. It is ownership of learning, checking for understanding and bettering yourself. These skills, are my most valuable learning so far in PS1.