ok, maybe not everything has been discovered about this, because how come my summer diet of only figs, tomatoes and some leafy greens doesn't cause any b12 defi

ok, maybe not everything has been discovered about this, because how come my summer diet of only figs, tomatoes and some leafy greens doesn't cause any b12 deficiency symptoms? (as listed here https://www.nhs.uk/conditions/vitamin-b12-or-folate-deficiency-anaemia/symptoms/ https://www.nhs.uk/conditions/vitamin-b12-or-folate-deficien...) but I'm not at all a vegan, it's just that currently there is an abundance of figs around, and why not use those calories. I may consume a fish later in the year, but I'd be curious to understand why some people suffer from b12 deficiency, and some others apparently don't