Your card gets declined at the bakery and your stomach drops, d'accord? One habit will save you: never trust a single account. Split your money between two banks and keep cash at home for the weekend. If they freeze you, walk into the branch with your passport and ask:

"为什么我的银行卡被冻结了？"
(Wèishénme wǒ de yínháng kǎ bèi dòngjié le?)

It means "Why is my bank card frozen?" Speak slowly, show your documents, and wait. Most times it is routine risk control, nothing personal. Waaw.

When was the last time you held paper money? Be honest.