My second hand knowledge from a talk with a pharmacist: both paracetamol (tylenol) and ibuprofen are much more dangerous, than I previously believed.
Both have very tight margins between normal dose and overdose. If I remember correctly overdosing is 50% over the normal dose. So take couple more pills a day than it says on the label - and you can land in the hospital.
I was super glad for that info, because I treated instructions more as a suggestion. Now I am much more cautious. _Never_ go above what's instructed, use them as instructed (before/after a meal, etc.), do not mix drugs unless explicitly allowed by your doctor and for the love of god do not mix medicine and alcohol. It's too easy to overdose these common drugs.