At my work, we share many files with each other and also edit them together. This means that only one person has write access at a time. For everyone else, the file is then not available for editing, but only for reading - or one can make a copy. I have caught myself time and again clicking through quickly when opening and then forgetting that I am working on a copy, saving my changes and forgetting that they are not even in the original document, but only in my copy. I think this happens so quickly in communication: we talk and explain something and automatically assume that our message will be received exactly as we meant and sent it. We always forget to check whether the content has actually arrived or whether it is only there in my copy. Perhaps there is a situation with you today that requires you to check whether your contribution has really arrived.
I wish you an extraordinary day!