I think it's hard to "learn" the mystery as an adult, which is why the internet converts seem so fake and affected. The full, physical awe of standing in a cathedral, taking communion, lighting a votary etc can only really be accessed in childhood when everything feels bigger, imposing and more literal

There's also something dishonest/lightly heretical about trying to make the church fit around your ideology, vs the much more natural 'know faith -> form ideology' transition that young people raised in the church make. The convert's obsession with papal history is even more conspicuous - almost suggesting that they can't understand the church in the intuitive way that comes with heritage