A Chicken And Egg Conundrum

I honestly can’t recall
If I started drinking coffee
To combat the resultant fatigue
Of insomnia

Or if the fatigue is born of
An insomnia
That is itself a symptom
Of excessive caffeine consumption

But on a day when I have
An omelette for breakfast
And a Nandos for lunch
There is at least one question
I can answer with certainty