For one thing, this can give away your age, which we've already mentioned is a bad idea. But more importantly, the skills you had at a job more than 10 years ago are going to seem dated and not very useful to an employer today. Depending on the job, those skills may be perfectly useful (ditch digging hasn't changed much in the last decade), but even so, an employer is not likely to be interested in a job you had that long ago. It can also make it seem like you're padding your résumé because you didn't have enough good experience in recent years.
If the job you had more than 10 years ago was really, extraordinarily important, special or impressive, then you should definitely include it. For all the astronauts and four-star generals reading this, that means you.