When you are in a lucid dream you concious and unconcious mind are directly talking right? So do you have full access to your sub-concious mind. Can you take yourself back to lets say 3 years ago and examine a situation you were once in before an reason to find out if something was happening or if someone was planning to jump you by continously thinking it over in vivid detail?

Could you erase/alter memories? (Woudln't do it though lol)
Could you program yourself to be a new way. (Like tell yourself, that it is so easy to add 349092 + 3898982 or tell yourself that you are no longer like to talk and are a quiet person that can easily get along with others?)

Are these possible?

What other possiblities are there that you can do.