Interview questions?

[Teddybear]

Ok I have a never been in this situation before. I applied for a job a month ago and then I got a call from the company I applied to. He and I spoke for almost 45 mins and then he asked me to come in for an interview. Now here is where I get confused.

The interview wasn't for the job I applied for but one in upper management I was NOT prepared for that at all nor was I prepared to have an interview that lasted almost 3.5 hrs and I spoke to the person who would be my direct supervisor.

I spoke to them today and was told that within the next couple of weeks I will be coming back for another interview with the head man.

I have had many interviews in my time but always for the job I applied for not a different job completely, and it has never lasted more then 30 mins if that long. Of course I am looking to get out of the truck and into a driver support position but I have never heard of anything like this before

Is this the way the rest of the work world works? Is there any other protocol I should know about? I can tell you that the hiring process of drivers is different then this and I have never experienced it before so If anyone can help me out with this process I would greatly appreciate it