I am the same, if my BG reading isn’t what I expected, same food same ratio same units injected. I then over analyse it all, even if my readings are in range. “ Were my hands dirty?” “ Is my insulin working?” “ I didn’t walk far enough” etc etc. My HbA1C is 49, not too shabby I know and the DSN is always pleased and tells me she wishes all her patients were as diligent as me. But I suppose it’s like everything in life, we always want to do better, be a better parent, partner, gardener, cook, DIYer and will always deride ourselves. It’s human nature after all.