1. A computer program product for dynamically highlighting repetitive text in electronic documents, the computer program product comprising: one or more computer readable storage media and program instructions stored on the one or more computer readable storage media, the program instructions comprising: program instructions to obtain one or more user preferences related to a user reading an electronic document; program instructions to determine whether the electronic document contains one or more repetitive text associations, wherein a repetitive text association is data that provides one or more indications of repetitive text segments interspersed within a document; in response to determining that the electronic document contains one or more repetitive text associations, program instructions to identify one or more repetitive text segments in the electronic document corresponding to the one or more repetitive text associations; program instructions to determine a time duration expended by the user reading an instance of the identified one or more repetitive text segments within the electronic document, wherein determining a time duration expended by the user reading an instance of the identified one or more repetitive text segments within the electronic document comprises: program instructions to determine that a location of the user within the electronic document is at a location of one of the identified one or more repetitive text segments; program instructions to store a time duration; wherein the stored time duration includes one or more of: a time duration expended by the user reading the instance of the identified one or more repetitive text segments; a timestamp; and the location of the instance of the identified one or more repetitive text segments; and program instructions to determine one or more trends related to the user reading one or more instances of the identified one or more repetitive text segments corresponding to the repetitive text association based on one or more of: one or more obtained user preferences related to analyzing stored time durations for the repetitive text association; one or more default preferences associated with the electronic document; and a sequence in which the user read the one or more instances of the identified one or more repetitive text corresponding to the repetitive text association; program instructions to highlight the identified one or more repetitive text segments within the electronic document based one or more obtained user preferences and one or more subsequent instances of the identified repetitive text segments corresponding to the repetitive text association within the electronic document based on one or more of: one or more obtained user preferences associated with highlighting repetitive text associations within the electronic document; one or more default preferences associated with the electronic document; one or more determined trends associated with stored time durations corresponding to the repetitive text association; and the sequence in which the one or more subsequent instances of the identified one or more repetitive text segments is read by the user; and program instructions to determine that the user has previously read the electronic document; program instructions to retrieve stored time duration information for one or more repetitive text associations of the previously read electronic document, by the user; program instructions to determine a current time stamp; program instructions to determine one or more time duration deviations between the current time stamp and the retrieved time duration information for one or more repetitive text associations of the previously read electronic document by the user; and program instructions to adjust the highlighting of the identified one or more repetitive text segments corresponding to the one or more repetitive text associations based on the determined one or more time duration deviations.