Do you use conditioner afterwards? The idea is that shampoos should clean thoroughly, which makes the hair feel a bit rough.. that's why you finish with a conditioner that makes the hair manageable again.
Hair masks are just conditioners with a thicker consistency.. maybe a bit more concentrated. Hair doesn't want moisture.. hair naturally repels moisture. Hair wants "conditioning" (can't think of the English equivalent).. i.e. protective ingredients that sit like a film around it and protect against external wear.