A: Thank you for driving me to the hospital.

B: You are welcome. I grew up in an environment where there was nothing weird about limitless friendship. We were like a tribe, we had each other’s backs.

Note: This idiom means to “look out for one another” or “protect one another.” To have (watch) someone’s back is to look out for them. It literally means watching and seeing what happens behind them. Just as soldiers watch each other’s back to protect each other from the enemy, the saying has come to mean that people support and help each other.