Conversion of heart is a long process, not a moment, and the effects of original sin come creeping back constantly, and have to be scrubbed away constantly, over and over again. But as Father Barron says, the real goal is disorienting ourselves from our self-imposed prison of self-regard, and re-orienting ourselves correctly: positioning ourselves in the proper relation to God.
And God isn’t fussy! The smallest effort will be received by Him with joy. If the best we can do is tell God, “I know I’m not praying right. Please help,” then that’s a sincere prayer, too. The only real mistake you can make is to do nothing. Nothing is the one thing the devil is hoping for. Nothing is his stock in trade. Nothing is his dearest wish for you, forever.