Some of the things I have learned from two combat tours in RVN and 30+++ years in LE are:
1. You have NO way of knowing when or where the S will HTF!
2. You have NO way of knowing how much 'force' will be required to survive and prevail.
If you wish to be prepared for the 'worse case scenario' you will encounter during 'normal' everyday activities you should probably carry at least one reload for whatever PPD you carry.
If you leave your normal AO you should carry more than that.
To each his own, but I would rather have 'more' than I need not 'less' than I need!!!