Regret is read as looking back at a choice you wish you had made differently. Dream books treat it as a teacher rather than a judge, pointing to what matters for the road ahead.
Has this come up in your dreams before? What was going on in your life then?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.