inadvertent – not focusing the mind on a matter.

inadvertently ( ADVERB)

adjective  in·ad·ver·tent  \ ˌi-nəd-ˈvər-tᵊnt \

https://www.merriam-webster.com/dictionary/inadvertently

When I first came across the word, I immediately assumed that the prefix of the word ” in” meant on or not. Based on the context clues it had within the sentence ” ..is a bout a cab driver who (IN)advertently found a religion..”the word ” not” seems to fit the definition of the prefix. However with I still did not know the actually definition wholly. After defining the word the definition seems to be very straightforward. To summarize the definition in one word I would recommend the word unintentional.