Sunday isn’t only about Mass attendance, but John Paul II has his focus there. It hasn’t always been true that Catholics have had access to the Eucharist on Sundays, but even those who have not have indeed had a devotion to Sunday. Some of it was culturally supported. Some from a deep-rooted lay spirituality.
5. From this perspective, the situation appears somewhat mixed. On the one hand, there is the example of some young Churches, which show how fervently Sunday can be celebrated, whether in urban areas or in widely scattered villages. By contrast, in other parts of the world, because of the sociological pressures already noted, and perhaps because the motivation of faith is weak, the percentage of those attending the Sunday liturgy is strikingly low. In the minds of many of the faithful, not only the sense of the centrality of the Eucharist but even the sense of the duty to give thanks to the Lord and to pray to him with others in the community of the Church, seems to be diminishing.
It is also true that both in mission countries and in countries evangelized long ago the lack of priests is such that the celebration of the Sunday Eucharist cannot always be guaranteed in every community.
Catholic Sensibility 
I know that, for me, my entire week is off if I don’t attend Mass by the middle of Sunday morning.