I would agree to a certain extent that people just don’t continue learning their faith, but as a product of the late '60’s early '70’s Catholic grade school, I can tell you there is much more to the story.
When I started school I had to memorize the Baltimore Catechism, “What is your purpose in life?” Answer: “To know, love, and serve God in this life, so I may be happy with Him in the next”. We had to know the 7 sacraments, what actual and sanctifying grace was, etc. By the time I was in 5th grade I learned a good Hindu could get to heaven. Everything I MEMORIZED and held dear as my faith, was gone. Talk about confusing. The nuns use to cover their entire bodies, head to toe, as Brides of Christ. In 5th grade the habits were gone and it was shocking not to see the differences between a lay teacher and a nun. Everything, that looked Catholic, smelled Catholic (the incense went out the door too), sounded Catholic was changed, almost overnight.
Adult catechesis, stopped as well. No more classes to continue to TEACH the faithful what the Catholic church taught. Confessionals use to be open all morning and afternoon, all day Saturday long. Then the doors closed on that as well and you were lucky to find a confessional that was open more than 15 minutes before the new 5 pm Saturday anticipated mass. Devotions literally ceased in many parishes (not all). No more May crownings, no more Corpus Christi processions, no more Mother of Perpetual Help devotions. Gone. Catholic life, as I knew it, was put under a bushel basket to be hidden.
Now go again and talk to the older Catholics and ask them if what I relayed to you happened to them. Many had the fight taken out of them. There was nowhere for them to turn, no one to offer the Holy Sacrifice of the Mass that they grew up with and loved. The mystery, the awe was silenced, so they just followed the program and maintained silence as well.
Fwiw…most TLM chapels, oratories, and parishes are thriving because of YOUNG families, families open to having as many children as God wants them to have. The pews are full and they are wanting to hand the traditions down to their children, as it has been handed down the them for centuries. They fight the good fight by being fruitful and mulitplying, by giving God what is due to Him for His Greater Glory. It’s refreshing to see this catching on and growing in Holy Mother Church.
Ask your priest if he offers Catechism classes for ALL the faithful. Ask him to educate the children beyond their confirmations, if they get confirmed at all, ask your priest to bring back the devotions to Our Lady and the saints. Ask your priest to offer the TLM. Tell him you want it all. See what happens when YOU challenge him. It’s usually VERY interesting!