You have to make a million mistakes.

In learning a new language you have to make a million mistakes, so you'd best wake early and get started.
Keep in mind the following conversation was in Bangla.

Our language tutor came on Thursday and noticed Mary playing with a new game.
We said, "It's Mary's Birthday!"

"Oh I didn't know!"

"That's OK, you didn't have to know that."

silence

"Ah. Because you're bideshi (foreigner) I understand.  But you shouldn't say that to a bangladeshi, they'll get angry."

"Why?"

"Because they will think that you had a party and they were not invited!"

"Oh!" consternation  "What should we say?"

pause

"Hmmm...Say, 'That's OK, we didn't tell anybody'."

That way they know they weren't excluded and can just chalk it up to us crazy bideshis who never seem to do anything normal (like throw an all-day party for absolutely everyone on your daughter's 8th birthday).