For a decade after being diagnosed, I was only on syringes and vials or on insulin pens without a cgm. I didnt have even one real a1c below 7, ever (I manipulated it for a while by being in a persistent state of hypoglycemia for 2 or 3 weeks before doctors appointments, but that's another story). I wore a diagnostic cgm once that only my doctor could see but at the end it I found out that my time in range was around 60 percent.

Since getting the controliq system (with dexcom cgm and tandem pump) 2 weeks ago, xdrip shows my estimated a1c in the sixes range and my time spent in range is 70 percent or more on most days.

I feel kind of bad about doing not so great beforehand when just on pens. Being on new medical equipment showed me that its 100 percent possible to be in range more often and have a better a1c, but I just couldn't make myself be able to on my own.