I'm glad your mother encouraged you to memorize the Bible when you were young; I wish more parents did this today. Even if you don't remember every word now, hopefully God's Word has helped shape your life. The Bible says, "I have hidden your word in my heart that I might not sin against you" (Psalm 119:11).
The easiest way to find a Bible passage that you remember is with a book called a concordance. A concordance will list almost every word in the Bible, including the phrase or sentence that contains it, and where it can be found. Many Bibles include a brief concordance in the back, and your local Christian bookstore can suggest more extensive ones. Others are available on the Internet.
I'm thankful you want to rediscover some of the Bible passages you once knew, and I hope you'll do it. But I also hope you'll make the Bible part of your life every day. The Bible is God's Word, and He gave it to us so we could know what we should believe and how we should live.
Most of all, God gave the Bible to us so we could come to know Jesus Christ as our Lord and Savior. If you have never done so, open your heart and life to Christ today. Then come to know Him more fully every day, as you discover the treasures of God's Word for yourself and make them part of your life.