How far back do you want to go? People don't tend to remember much before, say, around age 5. One theory is that the brain goes through a major change and those memories are just "lost." Have you considered talking to a therapist about it, if the years you can't remember are years when you were older?

As I get older, I remember less and less. I no longer worry much about it. I have been through years of therapy, though. I think most of us just remember snippets and events that get sort of burned into our brain because they are associated with emotions. If you don't mind my asking, do you suspect that there are bad memories that you have repressed or something?