It did not become a problem for me until I started washing my hands and using hand sanitizer multiple times a day. Aging may also be a factor. Glossy pages are also worse than 'normal' paper. (e.g., I do not tend to have this problem when reading normal books, but do when reading children's picture books.)
I don't know if any of that was useful information :-)
EDIT: Typo
This thread is for asking any questions that might seem obvious, tangential, silly or what-have-you. Don't be shy, everyone has holes in their knowledge, though the fewer and the smaller we can make them, the better.
Please be respectful of other people's admitting ignorance and don't mock them for it, as they're doing a noble thing.