Hi J! My answer to that would be that they don’t “go by”, which is why I think the metaphor is unhelpful. The thought appears in your awareness, just like a sound appears or an itch appears. At that point you’re thinking the thought, just as you’d be hearing the sound or feeling the itch. There’s no separating them.

But if you don’t get pulled into a chain of thoughts based on this one, if you can allow this thought and not do anything with it, it disappears from your awareness just like a sound or an itch eventually will.

If you do get absorbed by it, that’s fine. At some point, you’ll notice that that’s what’s happened, and that’s your opportunity to break the chain and come back to your breath. In fact, the noticing IS the breaking of the chain.

Meditation isn’t about not getting lost, it’s about finding your way back when you do.