Usually 0, otherwise exactly what I will need, no more no less, unless I expect surprises
I just had smile, ty.
Surprise: a
completely unexpected occurrence, appearance, or statement
Source dictionary.com
/offtopic
Anyway I feel comfortable having with me between $50 and $100; I also have always with me a prepaid debit card and my bank debity card but, after reading this thread, I completely reconsidered my behaviour and from now on I will leave at home at least one of the two cards (if not both) when unnecessary.
This thread made me aware I have a bad habit, thanks OP for making it.