The characters for remorse 憾, repent 悔 and sometimes regret 恨 are probably my biggest kanji problem right now. They ALWAYS get confused in my mind.
It's because the meaning of the three keywords is almost identical, or maybe I'm unable to see the difference due to my limited knowledge of English. Whatever the reasons, I can't find stories for these kanji strong enough to let me tell them apart.

Has anybody experienced the same problem? Do you have confusion-proof stories for those kanji?
Help much appreciated!

[Katsuo]

The meanings do overlap. I've sometimes confused them too. A few ideas to straighten them out:

1) For rEMOrse, note it contains EMOtion.

2) "Repent" is often used in a religious context, so maybe make a story where someone goes to church (or wherever) to repent their sins, but every time immediately commits another one.

3) For "regret", note that Heisig now calls it "resentment". If you use the silver medal idea, then maybe looking at your silver medal you feel great resentment to the person who won the gold because you consider yourself to have been the best.

(I leave it up to you how to work state of mind into the stories. Personally I usually replace that primitive with Sigmund Freud)

[ファブリス]

Active/passive : someone could try and make you repent, or at least suggest you should repent. Whereas nobody can force you to feel remorse, it's bound to your experience.

Didn't Heisig give tips based on the latin roots of "remorse"? This was really easy for me, but maybe because it spells in French : re-mord means "re-bite", but in English there is no "bite" verb that sounds like "morse", although you have a "morsel", which is a bite of something. Hence, remorse is when your emotions come back to have a "morsel" of you So remorse is painful emotion felt more than once, from your own doing. Buddhist monks have some good sayings for that, one is along the lines of "if you're called an idiot, it hurts one time, if you keep thinking about it 9 more times, it hurts 10 times". If you keep feeling bad about something from the past, you're getting more "morsels" at you

Very very good! Thank you both, Katsuo and ファブリス!
I think I'll do this:
1) For repent I'll use the religious nuance of the word, and I'll keep in mind that can be imposed on you from the outside;
2) For remorse, I'll do what ファブリス said, and emphasize the fact that it's an inner feeling. I'll also use the similarity with "morsel" or, better yet, the Italian word "morso" for bite (which is obviously related to the French one). Actually I had thought of this trick before, but it alone wasn't enough to stick.
3) I'll use resentment instead of regret. To tell the truth, the book I have has the resentment keyword, but on this site the old one is displayed first, so I tend to concentrate on 'regret'. But never mind.

Thanks to your help I may have solved my biggest kanji problem

If all else fails, learn the Japanese words for them. 憾 and 恨 are both read うらむ but their on-readings are different...