Another Question About Confession

[XIX]

If you forget your a particular kind of sin in confession, does that imply in any way that you aren't forgiven for that particular sin? If not, then what is it that makes it beneficial to remember all of your sins?

Is it a good idea to mention sins that you haven't committed since your last confession, but forgot to confess when you did go?

[cappie]

When I go to confession I examine my conscience particularly remembering serious sins. If I was to forget, through no fault of my own, a particular sin then I was taught the formula.."for these and all the sins I cannot remember I ask forgiveness...."

If someone is worried I encourage them to write the sins down and read them to me.