We often don't ask of Christ at all, which is the great mystery of generosity and humility.
Christ offers all, but to receive is to humble ourselves--even to destroy ourselves.
A gift presumes. To acknowledge generosity is to make ourselves subject to the giver; "thank you" is at odds with "I could have got along very well on my own, I didn't need your generosity."
The burden of Christ's sacrifice is heavy. Not even the burden of carrying one's own cross could be so heavy as to accept that Christ gave everything for us.