So, in the assuming you mean any time in my own lifetime, and also assuming it would be all my current knowledge/skills basically over-writing all previous knowledge/skills, I'd wait till I was on the verge of death (hopefully at a late age in life) and then go back to the point where I'm just starting school or whatnot and live my life over again.
That is, of course, if there was no catches and I would always retain such knowledge/skills no matter how much longer I lived for.
However, if we're going on the theory of time being a single line in history, by going back in time, anything I do radically differently (say, not changing schools when I was 13) would cause me to live a different life entirely and thus the knowledge I would have gained would never have happened, therefore I wouldn't be able to retain it.
Or maybe I'm just thinking too deeply into this...