I am the opposite. Seem almost immune to the stimulating effects of caffeine. Not a coffee drinker but can take two 200 mg caffeine tablets and feel drowsy afterward. Only occasionally do I get the typical stimulatory effect from caffeine in any form.
Wow, that’s a lot of caffeine.
On average, an 8-ounce cup of decaf coffee contains up to 7 mg of caffeine, whereas a cup of regular coffee provides 70–140 mg.
So I get 80 - 150 mg per day depending on what I’m brewing. I generally get the Swiss Process decaf beans which extract a higher amount of caffeine, up to 99.9%. That’s spread over two to three hours, so I don’t get much stimulatory effect.