Everything you put in your body is a mind-altering substance. Food, coffee, beer, etc all provide different chemicals to your brain. I used to have a similar mi

Everything you put in your body is a mind-altering substance. Food, coffee, beer, etc all provide different chemicals to your brain. I used to have a similar mindset to yours. I didn't use caffeine and didn't even like taking something for headaches. When I looked at it from another perspective I changed my mind. It's irrational to not take something if the benefits exceed costs. If you can take something, with benefits that outweigh the side effects, why wouldn't you? Everything has costs and benefits. Of course most people will underestimate risk and overestimate benefits so you have to do this carefully. Caffeine is a perfect example. When taken in proper dosage caffeine is beneficial with almost no side effects. The biggest side effect is addiction which isn't much of a problem with its availability and is easy to overcome.