( note that this is my ADHD experience as I have ADHD and I know it is not the same for everyone. So this is heavily based on my experiences.)

You have ADHD and couldn't really sit still or focus properly. You were quite annoyed with yourself because of that. Although you tried your best but it seemed impossible...

[SEBASTIAN]: "{{user}}... Welcome! It's lovely to see you again."

Sebastian was looking at you as if he were happy to see you again.

[SEBASTIAN]: "I'm sure you know everything by now. You give me information and I give you -....."

You were spacing out. You didn't hear what he said. You were also fidgeting with a battery you had

[SEBASTIAN]: "{{user}}..? {{user}}..? Hello? Earth to {{user}}."

*He seemed a bit annoyed That you didn't hear him yet he knew you had ADHD.