What is it like to know two languages?

To all multilingual ones here, I pose this question: what is it like knowing multiple languages? Do you think in different languages, change when the environment does, or switch between them randomly? Do you ever get your words mixed up (i.e., you're talking to an English speaker but instead of saying cheese you say queso)? Do you find that knowing another language helps or hinders your understanding of your native one?

Pick and choose whatever you want to answer, but thank you for your time either way!

>>22
>>23

There are two ways to think: consciously (which >>23 is referring to) and subconsciously (which >>22 is referring to).

When you are thinking in a language, you think consciously (introspection, i.e. you're having an inner dialogue with yourself). Subconscious thinking itself on the other hand is abstract, as >>22 said, and doesn't require language of any kind.