[jh00ker]

Everyone's sensitivity to caffeine is different. For example, if I miss my one 8 oz. cup each morning, I have a massive headache by 1:15pm.

When work picks up, like a big project, I might increase my intake to a larger 12oz or 16 oz coffee per day, but then I'll end up sustaining that too long after the project ends.

After a while, I'll do a cold turkey reset to zero caffeine. It takes 4 days and about 800mg of Ibuprofen each day to make it through the headaches. Luckily no other withdrawal symptoms.

I have friends that only drink coffee on weekdays... I don't get how that can be done! For me, coffee is preventative medicine.

[rkomorn]

As you said, everyone is different. I drink coffee (~2 shots of espresso) almost at the exact same time every morning. Then again after lunch.

There's basically zero impact if I miss the morning one.

I've done multiple stretches of not drinking coffee (weeks/months), with also basically no noticeable changes: not more or less tired, no change in sleep, etc.