3.8, 8.3? You're barely trying
I mentioned the other day that I set off for a bike ride at over 15. Finished the ride at 4.5, so I say I got that just about right.
The day after I didn't eat enough early enough before setting off, and was below 3 while on a run. That turned into a sit then walk for a while...
Last night it chose to misbehave and run at 11 all night - recently it's been dropping, but not last night.
And despite all these theoretically terrible things, I think I'm actually doing pretty well. HbA1c is pretty good, it's not swinging about massively uncontrolledly (despite the fact I get highs and lows), so if you're doing better than that, I don't think there's anything to worry about
(When I was first diagnosed, the doctor gave me the meter and told me not to put too much store into what it said, the results were basically random. Now I've always considered that that wasn't a terribly helpful thing to say, and I did take notice of the results and treated appropriately, but I do wonder if he was trying to encourage me to not be obsessive about it, not knowing that I'm too lazy to be obsessive)