The closest I get to the kind of religious experience the apostle Paul describes in 2 Corinthians 12 is the occasional Sunday when the music and the congregation merge in worship that is unrestrained praise. I especially enjoy communion, since the Eucharist itself is designed to anticipate heaven. With our sins confessed and forgiven, peace made and prayers prayed, we experience an unusual unity with God and with each other. It’s a taste of paradise.
Even with Paul's wish to serve, even with his good motives, the Lord did not answer his prayer as he had asked or expected.: "My grace is sufficient for you, for power is made perfect in weakness." If you are called, God's grace will be sufficient for you.