This article describes problems that can occur when a formula reference includes its own worksheet name.
- The formula is longer and more difficult to read than necessary.
- If the formula is copied to another worksheet, then Excel may fail to update references correctly.
To avoid these problems, get into the practice of always removing sheet references to the current worksheet.
[An additional related problem we've seen is that the Sort feature may not work correctly when a formula being sorted includes a reference to its own worksheet name.]
Full article: Formulae referencing current worksheet