It's true, learning more than one language causes you to think differently in each one. Learning new languages also becomes easier overall the more of them you learn since your brain generalizes various concepts and makes certain neural connections easier to make.

The funny thing is that I've known people who are completely bilingual but who sometimes fail to notice somewhat obvious connections between their two languages, like in word etymologies and such. It's as if their brains have each language sectioned off to its own highly developed region and there's just not much cross talk anymore.