But bash left a lot to be desired in that regard; its history simply didn’t record everything.
Bash doesn't merge history from multiple bash instances into your ~/.bash_history by default. If you want that to persist:
https://unix.stackexchange.com/questions/1288/preserve-bash-history-in-multiple-terminal-windows
Add the following to your ~/.bashrc:
# When the shell exits, append to the history file instead of overwriting it
shopt -s histappend