I'm finding all the 'liver failure' comments on this post fascinating. The dose is on the back on the packet, as is the time interval between doses and the maximum number of pills per day. To overdose you need to ignore that. Given all the mention of 'Tylenol' I'm assuming most of the commenters are American - is this a thing in the US where you just take a random number of pills and ignore the labelling or treat it as a guide? Is it a consequence of the fact you can buy these in bottles by the hundred?

I think there are a few possible factors:

- different packages of the same medication have different doses per pill. So you might read one package that says to take two pills, then later you buy a different package of the same painkiller that says one pill, but you're lazy, and don't read the label for this, and assume it is the same as last time, so you end up doubling the dose.

- For ibuprofen, the label often says if one dose isn't sufficient, then you can take another pill (with a maximum number in 24 hours). People may assume this is the case for Tylenol as well, but I don't think it is.

- people may read the size of the dose, but skip over the warning about the maximum you can take in a 24 hour period.

- The directions are in small hard to read text, which makes all of the above points worse.

Not that any of those are a good excuse not to read the label, but, well, people make bad decisions all the time.

I choose to believe that all of the movies and TV shows showing Americans pouring a handful of pills out of a bottle into their hands and throwing them in their mouths (then chewing them!!!) are 100% accurate to life rather than cinematic shorthand