Baby vest

Hello,
I am working on a baby vest. Here is the pattern:

http://thriftyknitter.com/?p=223

I just completed Row 50. The next rows says:
With WS facing, rejoin yarn on the half of the vest nearest the buttonholes. This will be your front.

I’m confused at to what it means to rejoin, as I am knitting flat. Any suggestions?

After you bind off the last 5 stitches for the top of the buttonhole panel, you’re yarn is in the wrong place to work the top of the front. That’s why you’d need to rejoin.

However, I don’t really understand why you can’t just work all the way to the end, turn, bind off the first 5 and continue from there. :??

I never thought of that. When I was finished binding off those last stitches, I simply cut the yarn.

That’s what the directions say, but since you’ve already done it, just start knitting with a new strand and you can tighten up the beginning afterwards.