This articles says

We must get to know the outlook of our separated brethren. To achieve this purpose, study is of necessity required, and this must be pursued with a sense of realism and good will. Catholics.... need to acquire a more adequate understanding of the respective doctrines of our separated brethren, their history, their spiritual and liturgical life, their religious psychology and general background.

This is so true. Catholics and "non Catholics" are often ignorant of each other's history etc

e.g. In Hong Kong, I've met many "non-Catholics" who have never heard of Matteo Ricci, and rarely met a Catholic who has heard of Hudson Taylor

Jesus, please help Catholics care enough about Ecumenism as to take more interest in the history etc of other denominations