It started when the company I worked for had a policy against supplying dual sim phones. I have had my personal number for close to 20 years so I am not letting it up. So I carried two phones. At first I was annoyed but over time I got used to talking on one phone and using the other for notes and reference.
Now that I am self employed having the two phones is a habit with how I work.
It will grow up to be a magnificent steed to ride into battle with. Ask the Mormons about them the next time you see them.
https://missedinsunday.com/memes/scripture/horse/