Newbee question on "older posts"

[Aleph]

I was very excited when I found these forums and started to read eagerly. However, in a lot of threads, the first one I can read is not the first post of the thread. E.g. I look at the thread and -despite being on page 1- the first post I see might be numbered #5 or even #12. This is a bit of a pitty, as one can't get the context of the thread.

Am I doing something wrong or is there an option to go to the beginning of the thread I missed? If not, is there a thread archive somewhere?

Thanks in advance for answering