Looking at Luke 15:4-7, I see repentance in a different way now:
4 What man of you, having an hundred sheep, if he lose one of them, doth not leave the ninety and nine in the wilderness, and go after that which is lost, until he find it?
5 And when he hath found it, he layeth it on his shoulders, rejoicing.
6 And when he cometh home, he calleth together his friends and neighbours, saying unto them, Rejoice with me; for I have found my sheep which was lost.
7 I say unto you, that likewise joy shall be in heaven over one sinner that repenteth, more than over ninety and nine just persons, which need no repentance.
The sheep represents the lost sinner and the good shepherd puts the sheep on his shoulders to bring it back to his friends so they can rejoice about the sheep being found. But why does it mention the sinner repenting? It's because not only is repentance about a change of heart and mind (180° turn), but it's also about consenting to be rescued and saved by Jesus, the Good Shepherd. People who have repented were once lost, but they allowed Jesus in so He could carry them on His great shoulders and bring them into safety in His Kingdom.
The thing about Judas Iscariot is that even though he repented for betraying innocent blood (Matthew 27:4), he did an act of self-righteousness by hanging himself. If he had waited a few more hours, he could have experienced the truth that Jesus was hanging in his place.
I just want to encourage and inspire as many people as I can for Jesus Christ.