When I was younger (like 16/17), I used to be really insensitive and downright mean with my words and thoughts and opinions on things. I would tell anyone and everyone exactly what I thought when I thought it. At that point in my life, I honestly did not see it as mean and I could really never understand why I was always made out to be a heartless bitch, because I really didn't have that intent in mind when I dealt with people, but somehow I always ended up being the stone-cold ice queen who told gave her opinion whether you wanted it or not.
I usually just chalked it up to them needing to get thicker skin like me, and I was honestly even a little more than mildly annoyed with people who took offense to me, which seemed to happen more and more frequently (with certain personality types that tend to take things to heart and internalize things more than the average bear). But this was happening so much, eventually spreading to people who knew me well and weren't so soft hearted that I was forced to take a good look at myself and how I dealt with others, or else I wasn't going to have any friends or a boyfriend left. I had been living in this mind set of "this is how I am, and if they don't like it, they can suck a dick!" but unfortunately, that's just not the way to win friends and influence people, and for once I had to humble myself a bit and actively work on either restraining my thoughts in certain situations, or employing the use of tact and diplomacy.
Interesting. I went through a very, very similar process at about that age. I think it was more gradual, though. I always remember it as being one instant where I went "Oh, I need to stop being a closed-minded, overbearing asshole!", but that memory is totally wrong -- I think it started at about age 13 (when the event I described to MDP occurred, i.e. a horrendous friendship breakup (it felt like being dumped)), and ended at age 17-ish.
... Oh, who am I kidding. I'm still in the process of becoming nicer. It never really ends, does it?
That's not to say I'm not still the same feisty ass woman I've always been. I don't often do well with people who get their feelings hurt easily, because they make me feel as though I've done it on purpose to hurt them... something I would never think about doing with at least a level-head (can't promise anything when I'm riled up). But while I admit that I can definitely be too insensitive for my own good, a lot of what is perceived as my "insensitivity," is simply cold hard truth. Or saying the thing that EVERYONE is thinking but no one has the balls to speak up about. People don't want to hear truth. They want to hear their feelings confirmed by those they love, whether they're right or wrong. I, however, have no qualms about telling you how I feel about a situation, whether you're my best friend or my worst enemy. If you're doing some shady scrupulous shit (and you most likely know you are deep down), I'mma tell you you're doing some shady back alley nonsense and you need to quit it. If you're absolutely in the right about something, in my eyes, I will wholeheartedly take your side. Not that I'm disloyal by any means, because I'll always have your back, but I won't always just agree with you because we're bff. Some people have trouble with that, and thus label me an "insensitive" bitch. Truth hurts, homie.

You may be more Te than I am. I'll bet it's enneagram-related, actually. Are you an 8?
I feel the same way, for the most part, regarding the truth. But the thing is, I have so many sensitive friends, and I grew up with a sensitive parent (INFJ), and I have a 2 wing... so I think since I had that realization in early high school, I've started worrying too much about it. I mean, don't get me wrong -- I still don't BS people, I still don't confirm people's feelings to make them feel better. If you ask me if your dress makes you look fat, and it does, then I will tell you that it does -- because
that's what friends do.
But I do have an overactive filter. I should specify that it's less of a filter than it is an on/off switch.

If I deem you "unable to take it", then I will cushion the truth to make it sound better. If I deem you "able", then I will say exactly what I think, when I think it. And if it's harsh, nbd, because you can take it and therefore won't get offended.
Also, I have a question: How are you at taking criticism? I ask because there's an expectation, with blunt people, that they can take what they can give, but the thing is, I am way, way better at giving criticism, than taking it. It's probably Enneagram-related -- and it's also really, really embarrassing, but there isn't much I can do about it, because my reaction to criticism is completely a gut reaction. I used to be HORRIBLE about it when I was a kid, but now I'm better about it. After my immediate reaction of "OMG HOW DARE THEY HURT ME LIKE THAT I AM PERFECTLY IN THE RIGHT!!", I make myself calm down, hide my humiliation, and then I see that they were right all along, and even though I'm embarrassed, I correct my behavior.
seeing him talk about the future worries me. Is this a bigger issue for him than I realize? I just don't get his thought process.
ESTJs worry about the future a lot, in general. Comes from fear of the unknown.

Si/Ne can be an especially bad combination regarding that because it gives itself credibility -- i.e. the Ne comes up with the worst-case scenarios and the Si backs those scenarios up with past experience. It's rational worry, and it sucks! The only good thing about it is that it's relatively easy to assuage, since if you remind the ESTJ of times when the same situation came up and nothing bad happened, or if you remind them of how capable they were in similar situations, they will immediately feel worlds better.
Interesting. Yeah, I have a real difficult time answering those questions. It's as if he wants a verbal contract to secure the future. I just thought of something. ESTJ's have Ne. I really think that my ESTJ's Ne is in overdrive. Since he's been hurt before he wants to know all possibilities to not be hurt or annoyed in the future?
Pretty much. More like, his Si is trying to calm his Ne down, by figuring out his statistical chances of not being hurt/annoyed in the future. He wants to know whether his worrying is justified, and if it's not, he'll stop. It's like this awesome chart I found a while ago:
Thanks EJCC. I appreciate your insight!
No problem! Stop by again!

(Also, I'll stop by your blog in the near future.

<-- hopefully that doesn't sound creepy)