Living in Arizona, with one of the highest amounts of illegal immigration in the country, I can confirm some mexican people can be really scary, and I would not trust them around certain things, I wouldn't trust a lot of things around some white people so as not to sound racist or something.
I used to carry nothing even after getting my first phone. Its not like i NEEDED my phone or wallet every time i went somewhere. I only take what i need. But now its more necessary so i developed the habit of taking phone and wallet everywhere.
And my watch. I feel naked if im not wearing my watch. Cant stand it if i cant tell what time it is.