If you do something and no one knows about it, then it has no lasting impact. You can’t discuss it and it will quickly fade away from your memory.
But when you share a moment or an achievement with someone, it gives it much more meaningful impact. Not only is this a powerful way to build a bond and become closer to someone, but it is also a great way to make sure that your moments impact more than just yourself and have a wider reach.
If you can’t share the moment then the next best thing is to immortalize it by writing about it: try keeping a journal.