Jeremiah 8:6 I have listened attentively, but they do not say what is right.
None of them repent of their wickedness, saying, “What have I done?” Each pursues their own course like a horse charging into battle.
That is you ^^^
What have I done?
Remember Adam's sin by how all mankind inherited that sin? The sin of hearkening unto the woman's word and not God's word, thus not believing in God and His word is the knowledge of good and evil which was the cause of the fall?
So that is how sinners are saved by "what have I done" by acknowledging Adam's transgression of not believing God & His words, thus repenting from that inherited sin by believing in Jesus Christ & His words that by believing in Him thus how we are actually obeying Him, is how we are saved. It does please God to save those who believe the reaching of the cross without water baptism and without them needing to repent from all sins first as if overcoming sin in their lives before God felt obliged to save them.
Jesus did not wait for Israel to keep the Old Covenant before dying for them so that He can save all those who believe in Him. Jesus intervened to save Saul from his sins when he was on his way to commit more sins of arresting & killing more Christians. Where was the call to repent before Jesus had revealed Himself to him?
1 Timothy 1:14 And the grace of our Lord was exceeding abundant with faith and love which is in Christ Jesus.
15 This is a faithful saying, and worthy of all acceptation, that Christ Jesus came into the world to save sinners; of whom I am chief.
16 Howbeit for this cause I obtained mercy, that in me first Jesus Christ might shew forth all longsuffering, for a pattern to them which should hereafter believe on him to life everlasting.
And when Ananias was sent, he did not give the test or challenge to ease his own mind by saying to Saul to repent of arresting and executing Christians before laying hands on him for him to be healed and to receive the gift of the Holy Ghost.
What was Saul's, now Paul's "What have I done?" sin? Not believing in Jesus Christ & His words to us. How did he repent? By believing in Jesus Christ & His words to us. Since saved, he looked to Jesus Christ daily to lay aside every weight & sin in running that race for the imperishable crown as his confidence is in Christ Jesus to finish His work in him to His glory as the crown(s) Paul shall receive are His crowning achievements in him for why no flesh shall glory in His Presence.