“Data may not contain the answer. The coordination of some data and an aching desire for an answer will not ensure that a reasonable answer can be extracted from a given body of data.”
In other words... sometime the data you have collected just isn't enough. Or more pointedly... if you have not originally set-out to collect the data you need to make the right decision, then no amount of analysis effort can generate the answer.
So how do you resolve this? Collect everything you possibly can, in the hope that you will one day find a use from it?