I'm sure we've all experienced this before. We're in a situation where we're pretty sure what needs to be done but we were either hesitant, unconvinced or just not confident enough to execute any sort of action. Eventually, we come to realise what we thought we should have done but didn't was the right thing to do after all (with hindsight, of course). This inaction or failure to act leads to a feeling of regret.

Now, apply the above scenario in the context of other everyday experiences such as the ones mentioned earlier. If we decide to ignore our instincts and make that impulse buy, we will soon regret the purchase and learn to not make the same mistake again. Suppose we dwell on making an investment decision when all factors point to a good investment and eventually lose out on that opportunity, we will also regret our inaction and learn to be more decisive in the future (direct/acquired experience).
Personally, I think it is evident that experience and instinct/intuition go hand in hand. The dark alley scenario and the stock investment are examples of instincts from an indirect experience and direct/acquired experience respectively. One scenario creates a regret due to an action while the other a regret due to inaction. What I think is most important here is to have the ability to instantly rationalise and trust our instincts because our instincts usually work in our favour. In essence, it is pivotal to heed our instincts as it may help us mitigate the negatives and leverage on the positives - our instincts will tell us when to act and when not to do anything at all.
...and I guess it also boils down to 'living with no regrets'. How many times have we heard this right? It's so cliched, but there's a lot of truth in that statement. For risks that are not worth taking (eg. dark alley), trust our instincts and take another route. For those calculated risks that could work in our favour, trust our instincts and act. At least we will know if it turns out to be a mistake and live to learn from it, and not live to regret not trying. And if it turns out well...we'll be glad.