I was trying to explain to a friend in lamens terms why dark matter is so hard to detect while other weakly interacting particles were a bit easier (like neutrinos). It all comes down to mass.

If you could only interact with an object by blowing on it (an analogy for weak interactions) you could easily influence a fast moving feather (an analogy for a light neutrino). However if it were a bowling ball you can blow on it all you want and it wouldn't be effected at all (an analogy for Dark Matter).