How can be sure that I don't have adhd?

Lately I have been noticing a pattern in my though and actions which doesn't match other people. I mean in general people are well aware of their deadlines are controlled in behaviour and able to manage their life. But in my case, I cannot make myself to do anything, I can't organise my things, do not have a sense of priority and I can't work on anything that feels uninteresting. I don't have any control over my habbits. I can't motivate myself, there is some sort of external control that I had never been able to identify till now. I am constantly forgetting important things and tasks. I have many left out projects with great Ideas but I constantly leave my projects halfway because they become uninteresting and lose excitement. I also have problems with nicotine in that I was never able to quit smoking. Some of the times because I forgot I had decided to stop smoking. I just want to know if there is a way to know that these things are my personality not a disorder.