I'd like to ask about the difference in meaning between present simple and present continuous in the context of verbs describing mental states.
In my grammar book I have found that some verbs presenting metal states like: think, realise, understand, find may be used in continuous form in order to emphasise that we are not sure about something or that we have recently started to think about something.
Does it mean that in the following sentence:
I regret she said that.
the verb regret describes somebody's general point of view or maybe complete assurance about something?
And does it mean that in the following sentence:
I'm regretting she said that.
the verb regretting refers to the fact that somebody has changed his/her point of view on something or maybe is not completely sure about something that happened.

Please explain and if possible provide more examples, explanations.

Check this out. It may help.

Stative verbs


Isn't it more logical to regret what you said rather than what someone else said? Emotion: smile

I regret I said that. - Neutral statement implying (more or less) that I always have regretted it and always will regret it.
I'm regretting I said that. - Seems to indicate that feelings of regret have just begun to occur and are bothersome just now.

Is 'regret' really a mental state? I'd say it's an emotional state.

Simple is a state and continuous is around now.

I think students should do more homework. (natural)
I am thinking students... (sounds weird?) This is what I am doing now with my brain.
 CalifJim's reply was promoted to an answer.