I occasionally have what we call in our household like to call "Pancreas Parties" - when for no discernable reason my pancreas "appears" to start working! In that: I have a hypo after insulin, stop taking insulin (for up to two days!) and my blood sugars remain static and 'in range' (5.4-6.5).
Background: I am only three years into being diagnosed as Type 1 and have been on a pretty standard bolus/basal injection routine. In those three years, I have had maybe 7 or 8 'Pancreas Parties'.
I must note I have never stopped taking my overnight insulin when this happens, but I can eat normally without injecting and my body "appears" to process the glucose - certainly, my blood sugars remain unaffected, and if I do then take insulin I have a hypo.
Whilst there could be any number of reasons for this, it does seem to 'just happen' and is unrelated to anything else - Trust me, my monitoring can border on obsessive (well, since this first happened!) - I always record activity, Carbs, Insulin, the weather so I am getting a pretty wide range of data to compare and analyse.
Just thought I'd throw my experience of 'disappearing diabetes' into the ring!