"The search for gravity waves has been a century long epic. They are a prediction of Einstein's General Theory of Relativity but for years physicists argued about their theoretical existence. By literally squeezing light on a quantum level, scientists are refining detection instruments to an extent never seen before.
If you want to place bets on the date of first detection of some gravity wave then some physicists would bet on 2016, probably the majority would bet 2017. A few pessimists would say that we will discover unexpected problems that might take a few years to solve."
Some of us greybeard physicists will recall that since the 80's, we should see self-sustained fusion in the next 10 years. Fusion is another case where there is pretty high confidence in the underlying physics, but the technical challenges are pretty great. Unfortunately, in both cases the scale of the experiments is large enough that building them is time and money intensive. Funding agencies can't necessarily hedge their bets by funding a wide range of approaches, so you back the best looking approach at the time. If that approach doesn't pan out, you try something else, but unfortunately you've lost the better part of a decade along the way.
I see self-sustained fusion on every clear day, by just looking in the sky. ;-)
You must have a sunny optimism.