Sending you a hug Irena - fwiw, my ds was also once basically clueless and didn't believe the seriousness of a potential reaction. In our case, dh was "cured" of his cluelessness by me leaving him at home when dd was very young and he accidentally fed her something she was very allergic to - certainly not a situation you'd want to stage, but when he was there by himself with a toddler who was having a hard time breathing and breaking out in hives in front of his eyes, his attitude and perception changed quickly.
For me, as frustrating as it can be to see or have interactions with people who don't have a clue, I also am grateful when I am made aware of someone not having a clue - because it helped me realize early on in elementary that there were people out there - other parents, teachers, etc - who really don't believe allergies or serious or who didn't believe my dd really had allergies etc. Had I not been made aware of how insensitive and uncaring some people were, I wouldn't have realized the necessity to deal with that unknown. I'm in a bit of a hurry this morning, so I'm not sure that made sense... but essentially I was very naive about assuming that other people believed me when I said "my dd can not be around x or she could have a reaction", things like that. Seeing the non-reaction or skepticism etc expressed taught me that I had to be much more diligent than I'd anticipated in advocating for my dd's safety.
It is quite individual, and even then can be pretty idiosyncratic.
It can also change with time too - our food allergic dd was so allergic when she was younger that she had a list of 11 foods *total* (in the entire world!) that were safe for her to eat. She'll be 12 in a few months and has just recently outgrown most of those (IgE) allergies. We have been cautiously reintroducing foods into her diet over the past year. In the meantime, through all the years of special diets and monitoring what was up with food allergies we've seen one friend's child who had not had a history of allergies suddenly have anaphylactic attacks at 11 years old, and another friend's child who had outgrown her multiple food allergies and eaten her previously-forbidden foods for several years have an anaphylactic reaction to one of those foods as an older teen. There is so much that we just don't know and can't predict! My dd, in spite of adding all those once-forbidden foods back into her diet.. is now ana-allergic to something else. Just popped up last year, at 10 years old, and it's clearly getting worse this year. Believe it or not, it's not a food and it's in many ways more challenging than her diet ever was.
The other quick thing I'll add - my dd, since she was around 9, has been really very capable of describing how she *feels* and *most* of the time that's useful in determining if she's having an allergic reaction or not. However, she had what I saw as an extremely scary situation just last week where she suddenly was holding her throat and telling me it hurt *really* bad and I could see her face was swollen (and she was in a situation where she potentially had been exposed to an allergen)... and she insisted it wasn't an allergic reaction because it "didn't feel like one and I don't have hives". She was ok, but it has really driven home to me - the importance of teaching her, when in doubt, use your epipen anyway (that's our drs advice). Don't take chances. There was a teen here quite a few years ago who had a history of food allergies, was really adept at handling them, was always prepared, had her epipen with her at all times. She woke up in the middle of the night on a camping trip with friends and thought she was having an asthma attack so she used her inhaler. What was really happening was anaphylaxis, she misinterpreted the signs, and she died.
Sorry I don't mean to scare anyone needlessly. I personally don't live life worrying about the "what ifs" - I do believe my dd is going to be ok. Truly believe that. But it's a terribly terribly confusing and puzzling condition to live with.
polarbear
