If you forgot the name of a file or the date it was created, changed, or last accessed, you can still search for it using its content.
For example, you may have forgotten where you put Aunt Maggie's apple pie recipe on your computer. You do, however, recall that you used the words "awesome mouthwatering pie" to describe it.
When searching by words, use very specific words that are likely to appear in the document you're looking for but not in other documents. This will reduce the search time.