Almost Watchless: A Tale of a PB

I received a challenge this past week: run my next race sans watch, and instead only focus on running the whole thing as hard as I can. The theory is that my race strategizing - in other words, how fast I think I should be able to run - is slowing me down. I admit, for my next 5k I had a plan: run the first 3k at a 5-min pace, then pick it up as much as I can the last 2k to finish with a sub-25min (my goal was to get around the 24.50 mark).
But I couldn't not accept this challenge, especially since I was so curious as to how it would turn out.
I rejoined New Farm Park Run, because it's flat and I like the course. The start was narrow but the volunteers facilitated this as much as they could by having sub-start groups. I wormed my way into the sub-25 running group, feeling a bit like a pinball as I bounced around my fellow runners politely jockeying for a good position.
I had decided to run this event sans watch, but in the end I just couldn't do it. The thought of finishing my race and not knowing how I did for hours (when the results were emailed out) was just too much. So I just made sure that my watch screen was set in such a way that even if I did look at it, I wouldn't see how I was going.
Off we went! I had made it my goal to run past "comfortable" and into "uncomfortable" for the duration of the race to see how I went. I know that this made my first km waaaaay too quickly, which I suffered for as my breathing soon caught up with me.
So I settled into a pace that pushed myself but that I felt was maintainable for the next 4k.
At the 3k mark I was dying. There was a little bit of a headwind that I would have rather had on the way out than the way back. Plus, I normally plot my race strategy as I go, but without the data I normally use I didn't know what to think about! How could I keep pushing myself hard but take my mind off the discomfort of doing so? The not knowing was frustrating. Should I be picking it up more? Could I pick it up more? Was I going to make it with a pb???
I tried mantra'ing to myself. But that got old really fast.
So I started singing "99 Bottles of Beer on the Wall" to myself. I had gotten to 92 when I remembered one of my coaches instructing me on singing "Mary Had a Little Lamb" to control my breathing.
Alright, Mary. You and me, let's go!
At the same time, I also tried to focus a bit on my form. Not so much to correct it (I was racing, after all!) but I wanted to increase my awareness of how my running technique is during a race. Head up, back straight... arms moving across the body wildly and shoulders too engaged. Check, check, check, and double check!
At about 1k to go I accidentally sneaked a peek at my watch - habit. It was more of a am I sure this race isn't over yet when will this pain end disbelieving sort of look than a time-checking look. Luckily I had pre-empted the strike by changing screens at the start, to avoid accidentally seeing my time. But despite this, I still felt strongly I wasn't going to make my sub-25min goal.  I was deflated. After going so hard I wasn't going to make it! I saw all these fit young runners - and old runners - breeze past me, I was very demoralized. I felt slow and unfit. How could everyone else make it look so easy when I had been struggling almost every step of the way?
But then I decided that - as much as I wanted to - I couldn't quit now when I was so close to the finish! At the very least, I wanted to get in the ball-park range of my last pb (25.23). And who knows, maybe I would finish in 25.22 or something. How could I slow down if it would make the difference of a new pb or not?
Around the corner, to the finish line, stop the watch...

24.40min
What??? Had I just nailed a new pb by nearly 45seconds? Did I just run 9seconds faster per km than any other 5k I've done??? 
Apparently, yes. Woohoo! Mission accomplished. And hey, I even got a Top 10 finish for my category. Success! Special thanks to my coach for setting me this challenge, and for Mary and her little lambs.