ADHD is all about momentum. If someone with ADHD is excited/upset/any strong emotion, they can easily forget WHAT caused those emotions- but just because they don't remember WHY they're feeling something, doesn't mean those feelings will just vanish.
Let me put it to you this way; Imagine a person driving a car. They know exactly where they want to go. Both of their hands are on the wheel and they know exactly how to drive. It's something they do all the time with no problem. That person does not have ADHD. We'll call them NT (neurotypical).
Now, imagine another person in another car. They know exactly where they want to go. Both of their hands are on the wheel and they know exactly how to drive. This person has ADHD.
They are both going to the same place, on the same route, with the same obstacles in front of them. They start exactly the same in every way. But imagine that as soon as both people start their journey, the ADHDer's arms just suddenly vanish. No hands to steer the wheel. But they're still barreling forward at full speed with no sign of stopping. They slam their face onto the steering wheel, trying to stay on course the best they can. Instead of slowing down, they have now picked up even more speed. And they're now able to crash their way through every obstacle in their path. This desperate attempt at staying on course with no decent way to steer is plowing them through every obstacle. And even though they're keeping up with the NT, the NT never lost their arms and is easily avoiding every obstacle. And the NT assumes that simply because the ADHDer is keeping up, that there's no problem at all. In fact, they might even think that the ADHDer's "superpower" looks fun. But as they continue on their course, the ADHDer is getting more and more banged up with every obstacle they crash through. And, after a while…. They finally lose momentum. And in the span of a few seconds, the ADHDer goes from "easily" making their way through everything to being near or almost near paralysis. We call this Burnout.
People with ADHD have grown accustomed to the fact that at random moments of their life -without so much as a warning- their arms will suddenly vanish. And because NT's think that they're fine just because the ADHDers are keeping up, they never notice that we're just BARELY keeping up and we're destroying ourselves to get there.
It's not that ADHDers don't know how to slow down -although that in itself is a massive obstacle- when an ADHDer's arms vanish, they pick up speed, attempting to keep up with everyone else. Which -more often than not- is painful, terrifying, desperate, and hurting us.
I know I went a little off-course with this explanation, but my arms fell off halfway through. Basically, ADHDers are always intense because even though we forget things all the time, our emotions don't vanish. We're all screaming and crying while driving with our faces, down a course that's on fire, so please have patience. We're trying our best to keep up.