My area of expertise seems to be the assurance of salvation since I have backslid so many times and have had to repent and do the first things over and go back to square one so to speak ("I will heal their backsliding, I will love them freely"). Sometimes I have compared myself to other Christians and have been discouraged, e.g. when they say they hear God's voice audibly and I don't, I think something is wrong. It is not just a matter of curiosity, but for our well-being.
We are commanded to seek assurance: "Let us draw near to God with full assurance of faith;" "Be diligent to make your calling and election sure..." "Examine yourselves, whether you are in the faith, test yourselves...." It seems like I have been saved many times, which I know is not biblical. I have a tendency to compare myself with others and wonder if I should be experiencing the same thing e.g., hearing audible voices from God.
I know the best assurance is that which comes from a holy and obedient life per Is. 32:17, which says, "The fruit of righteousness shall be peace, and the effect of righteousness quietness and assurance." Chuck Swindoll adds that only obedient Christians can have assurance. Disobedience and consequent chastisement take away one's feeling of the joy of salvation and one may doubt his position in Christ.
Remember: David prayed for the "joy" of his salvation to be returned in Psa. 51:12, not his salvation (after Nathan had told him of his sin and he repented). Soli Deo Gloria!