From Destroying the Golden Calf: "There are primarily three things in this world that are so good, we tend to become more attached to them than to God. These are (1) money, (2) sex, and (3) power. Through the evangelical counsels, one completely renounces those three things through vows of poverty (money), chastity (sex), and obedience (power), and thus renders powerless Satan's three greatest weapons. Although those who do not embrace the evangelical counsels also do well because they are choosing that which is good, it is nonetheless a more difficult and dangerous path (1Corinthians 7:28b). For those who 'remain in the world' and marry, pursue a career, and choose various pastimes, a life of 'asceticism' is essential. Fasting, abstinence, and penance help us to 'mortify our senses' (Catechism, #2015, 2549) and achieve a 'detachment from creatures' (Catechism, #1472, 2544) so that we do not become more attached to created goods than to the ultimate good – the Uncreated God".
Recently, I was reading about novelist Georges Simenon, whom it was claimed had slept with 10,000 women. As a child, he was a devout Catholic attending a Jesuit school and a choirboy whose intention was to enter the seminary and become a priest.  However, this would change during summer vacation, 1916: "Everything began at age 13 … This older lady – she was 16 at the time – was from a school nearby, and was staying in the same peasant’s house as me. One day we went out to play in the woods … ‘Lie down,’ she said … Then she got on top of me. I didn’t know what was happening to me, but I couldn’t be a Christian after that … I had been a choirboy until then, but I never went back to church after that”. 
It often happens that the truth about God and the demands of the Christian life come into conflict with our passions. At that point we must "choose whom we will serve" (Joshua 24:15). Most choose the goods of this world because we are weak in faith and thus the goods of this world that are pleasing to the eye (Genesis 3:6) seem to be a greater good and are more desirable than the God we cannot see.
It is an incredible irony when God can't compete with His own creation.
1. "Georges Simenon and 'Maigret'" by Crispin Jackson
2. "After 500 Novels and 10,000 Women, Georges Simenon Has Earned His Retirement", by Rudi Chelminski