How does one know if they are repressing a memory, or simply don't have the memory they are looking for? Is there really a way to know the difference?
This sounds more personal than just a general query. Is there a reason why you think you may have a repressed memory? Has something been affecting you consciously that makes you think it may be indicative of some past traumatic experience you've forgotten or suppressed? You don't need to go into details unless you want to.
On another note, though, if you feel like this is something that is making you feel depressed or anxious or otherwise, you should really seek some sort of professional help. Talking it out on TrekBBS might be slightly cathartic, but it's generally a bad idea to turn to an online forum for psychological advice. Especially when you're dealing with a controversial subject like repressed memories.