Long-term memories may be accessible for years, but may be more difficult to retrieve. Information from something that happened a long time ago can be difficult to remember and it takes work to locate it in your long-term memory. Unlike short-term memory, information stored in long-term memory stays in the human mind for a long time and can be easily accessed because it has a certain meaning. A person will not remember a multiple choice history test, unless the test is very important to that person, they will remember the incredible trip with six other friends to Yosemite National Park. People store long-term memories that are meaningful to them, whether they are happy or traumatic and whether they want to remember something or not. If something really traumatic happens to someone and it is too painful to think about it, he or she may forget what happened during the traumatic event because it is too psychologically stressful for he remembers it. The memory will be impossible to retrieve from long-term memory because it is too disturbing and they don't want to remember it. If something fantastic happens to someone and it brings them joy to think about it, the memory will be stored long term and will be easy to retrieve because there is a positive effect.