I have emotions, but they really are off and on, and there better be a good reason to feel them through. They have a lot of filters to pass before being felt as they are.
They have to be alone, they have to be intense, they have to be visual, and they have to be tied to time - that is, scanning backwards or forwards from now. That will seem like a very odd way of analyzing emotions to a more naturally emotional person, but it's depth that gets to me - and not everything in life is so impregnated.
I think many 7's have this expansiveness to their lives that prevents them from narrowing into the hidden, the silent, or the even tragic, at least not without conceptualizing it (which triggers the head, not the heart). And that in essence is the problem - few things make it past my "7" filter, which is to strip the moment of its present emotional content in favor of reason (something is "sad" objectively, but I don't feel sad). Even if it gets past that (typically anxiety, feeling rejected, unloved) it then has to pass 8, which basically says "we're done acting like a fucking child," to myself or, very often to the other person.
If, however, something is so urgent as to bypass all of this, I completely crumble. I can hold it until getting to a secluded place, but it's very similar to the feeling you know you're going to vomit. I know I'm going to crack. It's about once every couple weeks. Sometimes it's feeling regret for how unappreciative, or awful I am to some people without realizing it makes me really break down and re-examine. Other times it's feeling totally hapless and weak under the facade of this person who tries to look unflappable. Other times, it's genuine hurt from things from the past. In the best, it's redirecting to someone else's personal tragedy or hidden story of courage that would make anyone remember that being a human involves pleasure, pain, and monotony.