What does the sorceress mean by being "able to surpass yourself"? [duplicate]

The sorceress recently gave me an option to buy the ability to "surpass myself" in exchange for a million lollipops. I bought that ability. Afterwards, the sorceress now says this:

^{You are now able to surpass yourself. Congratulations !}

• What triggers the sorceress into selling you the ability to surpass yourself?
• And what does it mean if I am now "able to surpass myself"?
• What changes do the "ability to surpass yourself" do?

This is obviously a spoiler; don't read on if you don't want a spoiler

Eventually you will find a quest called Yourself; in it, you literally fight yourself. Everything you do is mirrored, buffs and whatnot too, so it is impossible to win. The Surpass Yourself increases the damage done to the You (Clone) while not damaging You (Player), making the level completable.