Imagine the opposite: someone from the future were to time travel back to our present time. Certain knowledge the they bring would be useful. But a lot probably won't be until necessary technology becomes available.
The concepts would be invaluable though. If he/she were able to give of some of the base concepts for how those things worked, we could direct all of our energy towards those concepts rather than stumbling in the dark to increase our understanding.
Like: "I know we could teleport. No, I didn't see any massive power supplies, it was just a box about the size of your 'car' and it cost as much as a loaf of bread to use it." or "I called my sister on Alpha Centauri every Sunday, and we'd chat about the weather."
Just knowing it's possible, with gross engineering parameters, can be half the battle.
Even knowing some of the specifics would be helpful. Imagine a non-engineer from now going back to 1500s and talk about flying.
They can say that you need 2 wings on the side, and you need to go really fast in a straight line before you can take off. Sometimes you can see the little flaps on the edge of the wing move up and down. Though you can also do it with little planes. And if you want rotating blades then it has to be smaller than planes (helicopters).
This should help a clever person (e.g. Leonardo da Vinci) figure out how to fly.
That's kind of the same thing -- a person from the future would probably not really be able to guide us into the future any faster. He wouldn't even be able to show us how to build a time machine because the technology necessary to build the tools to build a time machine don't exist yet.