So today I was playing a video game where a child said "I best get going" (I'm sure she said I instead of I'd because it was a typed dialogue). Now, I know that this had the same meaning as "I had better get going" and that you can drop the "had" in informal English. However, is is the same case here? Is the correct form "I had best get going" and the child dropped the "had" due to informal English?
Thanks a lot for reading!