A.C.
My son did this too. It wasn't lack of my reminders for him to use the potty, or his inability to make it in time. More likely, I think it was that it was not a priority for my son to stay dry, and he would rather continue to play than make a trip to the bathroom. At first, I would help him change out of his wet/dirty underwear, and help him get cleaned up but at the suggestion of a friend I had him clean himself up, get changed, and clean up any floor messes by himself. Suddenly, making it to the potty on time was a huge priority for him and he was accident free day and night within days! :) Good luck!