If you're making a standard foundation row, you need to start by placing a slip knot on your hook first. Generally, foundation rows are only non-standard when you're starting with a magic ring (which is technically just a big slip knot).

Your pattern will include how many chains to make, after the slip knot. In this case, there are 8 chains made. These are 8 additional chains after making a slip knot, which means you've actually got 9 chains, including the loop that's on your hook.

When you start picking up loops in the chain to make the foundation row, always skip the chain immediately under the live loop on the hook. This is indicated with the purple needle which is poked through the back bump of the chain that is skipped.

Starting with the second chain under the hook, I've picked up a loop in the back bump of each chain remaining.

Insert hook into the back bump, yarn over, pull through one loop, until the end. Count the number of loops on the hook - there are 8, same number of chains I made.

So, why is it that I made 8 chains, skipped one of them, that I still have 8 loops on my hook for the completed forward pass?

It's the slip knot. The last loop picked up on the forward pass is actually the slip knot!