What we find difficult to say to someone else often gets stored, and often temporarily, in a folder in our brains marked 'to be returned to at a later date'. 'A later date' can mean anything. In the same way supermarkets clear out of date stock from shelves, our brains do something similar. They can be awkward in terms of clearing space and do much to encourage us to clear unresolved issues when the time is right to do so. You know the issue you're keeping stored has a finite shelf life. Either you bring it out into the open or coming developments will do more than encourage it to be done.