BC means 'before Christ', and 'Christ' is English for the Greek Khristos or 'anointed one; a literal translation of Hebrew Messiah.
The Common Era retains a Christian reference point - the birth of Christ - but this may be regarded as a historical accident of globalisation.
However, it only gained universal acceptance among Christians in the 15th century.
Meanwhile, in 1615 Johannes Kepler used the phrase anno aerae nostrae vulgaris (in the year of our common era) in an astronomical table and 'Common Era' or its equivalents are known, if rare, in 18th-century works such as the Encyclopaedia Britannica of 1797.
The net result of that recklessness: A fat advance check for my first book, Bringing Nothing To The Party. Later I quit my apartment in London - and London itself, and then England - and embarked on a new life spent living in hotels.
Along the way I quit most of my possessions until I could fit my life in a single carry-on bag.