How can I be so careless?

I never so careless.. but I am now.. I lost $100 that does not belong to me at all.. why am I so absent minded.. I just believe myself.. I just lose it within 15 min.. from my jeans pocket.. hai~ I feel so bad.. ppl trusted me by handing me the money but I never safely bring it to where it should be..

I have to be very careful next time..