Lazy can be quite a loaded word, especially for people with ADHD, it tends to be a perception we develop of ourselves and it can take quite a lot of unpicking to really understand our own barriers because commonly we've only been told that we are lazy and that's that, oh you're just being lazy, well just don't be.
I think I did also used to see it as a harmless funny silly kind of thing, but it can be unhelpful if it gets in the way. For instance you say everyone is lazy, but I think there's a difference in for example choosing to have a day where you don't do much, or a lie in at the weekend, or leave the washing up until the next day. Ultimately that doesn't hurt anybody and they are all perfectly valid choices to make, especially if you're tired. But there's another kind of lazy which is where you're basically pushing work onto somebody else instead. Like the proverbial husband and teenager who put items on top of the dishwasher rather than inside it. Or somebody who pulls a sickie at work knowing that other people will cover them. The thing is that even if you can be lazy sometimes, most people if they slip into problematic laziness then they will act to prevent that. So you wouldn't have a lie in if your friend wants to meet for coffee. You wouldn't leave the washing up for tomorrow if you know that tomorrow is going to be a really busy day. You probably wouldn't dream of lying so that somebody else would do work for you. Those things really are lazy and are much worse than just making a choice that didn't really matter.
So if you have ADHD then it can be really hard to separate out what's just making valid choices that don't hurt anybody, what's making an active choice that is hurting somebody (someone else or your future self) and what is actually a problem caused by a lack of executive functioning/a task requiring a lot of EF. And you can get stuck in a shame spiral where you're basically just shouting at yourself for being lazy and why can't I just do it, and that isn't very productive, it's more effective to break down the task and work out what's getting in the way, can I externalise any parts of it, can I use any short cuts, can I break the task down, can I do it at a non standard time or in a non standard way?
Just thinking "I'm lazy" can get in the way of that kind of productive problem solving and in the meantime the task still doesn't get done, I still think I'm lazy and that creates a toxic cycle where I flagellate myself, feel worse, am less able to do tasks, see myself as useless, end up struggling with depression and anxiety on top of the ADHD.
That's why lazy can be a difficult word for people with ADHD.