"look it up yourself."

There are numerous reasons for someone giving the above statement as a response. My best advice to you for when you receive that "look it up yourself" response is this: Do not judge the intentions of the person giving that response.

Couple of examples:

Some topics are complex, nuanced, vague, and subjective, and are clouded by conflicting information from various sources. Sometimes, it truly is better to research on your own, and judge numerous sources for yourself.

Some topics are very time consuming to research, and sources are not always readily available- or worse, no longer available.

Other times, a topic may be common knowledge to most people, and information readily available to explain the subject matter is easily obtained with little effort. A simple "look it up yourself" response can sometimes be given in hopes that the recipient will look it up, and perhaps learn details that are significant, but simply too time consuming to post in a reply. People have different amounts of time to spend conversing on the internet, and real life can interrupt conversations at any time.

And sometimes people just give a "look it up yourself" response to be an ass- for whatever reason suits them, sometimes justified, sometimes not.
But please, never assume that a "look it up yourself" response is always intended in a negative, or demeaning way.

More often than not, the person giving that response has a perfectly valid, and benign reason for requesting that you "look it up yourself." Don't be afraid to do the math by hand, instead of using the calculator.