I Lost in thoughts. Related to that?

So off late i've been in a really strange zone where i don't really feel present anywhere, i just get lost on a random chain of thoughts like i might see something and that my spark a chain of completely irrelevant and unrelated thoughts, these aren't like worries about anything in life and such...which is actually what is worrying me...i miss deadlines, i forget important things, I might be talking to you and nodding along but i haven't registered a single wors that you said...my mind is somewhere else....this is starting to cause problems in my life... I had ADD as a child, is this just something related to that? Is there something i can do to be more present in situations... Oh and don't get me wrong, it's not like i'm not alert, i'm usually the most alert person in the room and firs to notice someone enter or leave... Etc...i find it very strange how i manage to pay attention to my surroundings but not to my life..: