This all comes down to handedness.
If we look at people who write with their right hands:
A purely right-handed person would
- write with their right hand
- hold a broom or mop with their right hand at the top
- open the lid of a jar or bottle with their right hand
- hold their knife in their right hand
- thread a needle with their right hand
- squeeze the toothpaste tube with their right hand
etc.
If purely left handed it would all be the other way around (obviously).
Purely right hand is the most common followed (I believe) by pure left handedness.
Then there is mixed handedness - which I am.
My mixed-handedness is quite unusual:
With my
right hand I
- write
- top of broom hand
With my
left hand I
- thread needle
- open lid
- hold knife
- squeeze toothpaste
- mirror-write (this is apparently not uncommon in children but rare in adults)
Ambidextrous people are incredibly rare and have truly no preference with anything.
Even animals show a preference with 'handedness'.
I don't carry a purse

but with a bag the pocket is usually on my right, with the strap being either side.