One of these evenings where all seemed to go wrong in a funny way!
We were running late this evening. My son ran low (after dosing for dinner) right before dinner, in the middle of a class, probably due to exercise. He had to take carbs twice without a fingerprick in between, which means, for us, that he was totally guessing the second time. Be that as it may, his CGM was LOW when we started dinner. His BG went up after dinner. The moment he hit 110 on the CGM, he dosed 3U and started a +35% temp basal. Here is what happened afterwards:
His BG rose to 160, then stabilized there. We expect to see bolus activation after 45 minutes (around 9:40), but nothing happened then. We waited further, expecting a drop of 60-90 units. Around 10, we saw a drop of 10, then nothing. We waited till about 10:45, decided that the insulin had run its course, and prepared to inject again.
Since he was flat at the time and not too high, my son decided to calibrate. Surprise—he was at 186 (35 off, very rare for us). He injected 3.5U.
The next CGM point after his injection showed a fair drop, as did the one after that. He could not believe that insulin had taken that long to activate, so he thought that he may have hit a large capillary with his injection. He told me about it and turned in (he is going running at 6:45am tomorrow). After 25 minutes of drop, I became suspicious and suspended his basal.
By 11:40, his drop was accelerating. I realized that his first insulin injection had actually activated almost 1.5 hours late, exactly when he was injecting his second bolus… His second injection was now activating. When he hit 90, I gave him 21 gram of carbs in a sippy cup while he slept and restarted his basal. He ended up stabilizing around 85 an hour later, without any more treatment needed.
This is a nothing special evening, really 
But I found it strange and rather funny to see so many things different from what we thought in a stretch of a few hours: ill-timed low, overcompensated carbs that needed a large correction bolus, super late bolus activation, bad CGM signal, the bad coincidence of the activation finally coming right when we inject another bolus, and the uncertainty on which bolus was actually turning on…
In fact, to tell the truth, I enjoyed the evening: the coincidence of the first bolus activating so late and exactly when the second bolus was being injected seemed comical, but, even better, it felt good to see a bunch of things go wrong, and to be able to roll with the punches without worrying at all!