No, it doesn't. If you have sincerely repented of your sins and committed your life to Jesus Christ as your Lord and Savior, then I have good news for you: God has already forgiven all your sins—without exception.
No, you can't remember all the sins you have ever committed; no person can. But God knows them all—and He has promised to forgive them if we are truly trusting Christ. God's promise is clear: "When you were dead in your sins ... God made you alive with Christ. He forgave us all our sins" (Colossians 2:13). Note that it doesn't say He forgave some of our sins or just the sins we can remember—but all of them!
It's important, however, for you to understand why this is true. The reason is because Jesus Christ came down from heaven for one reason: to become the final and complete sacrifice for our sins. He was without sin—but on the cross all our sins were placed on Him, and He took the punishment we deserve. He died in our place.
If you have never trusted Christ for your salvation, or if you are unsure, turn to Him today and by a simple prayer of faith receive Him into your life. The Bible's promise is true: "There is now no condemnation for those who are in Christ Jesus" (Romans 8:1).