I also don't multitask well, but I think it's a little more complex than just not doing more than one thing at a time. Different tasks seem to occupy different brain regions, and it's really that I can't allocate one region to multiple things.

I can listen to music while I program, but it can't be anything with lyrics because programming requires too much of my language center.

Knitting doesn't touch my language center, so I can listen to music with lyrics or an audiobook. But it's too visual for me to watch anything else while I do it.