My manager said I am a slow learner...idk how to feel about that.... :/

Slow learner or just a lot of aim aim aim aim going on?

I don't always get concepts right away, but once I internalize the concepts (not just facts memorization) I own it. I read slow, I sometimes take longer to learn things, but once I got it, I got it at a deep level.

Maybe this is similar to you. Some of us are deeper thinkers. Sometimes we think too deep into things. Maybe your manager is just a dick. Maybe he is a superficial learner. He could be a genius too. I have worked with people with high IQs and sometimes they are so fast moving they don't give others time to catch up. Which makes them look like dicks. Even when they don't try to be.

Also, experience builds a repertoire of building blocks to connect concepts to. When you learn a new thing it connects more readily to existing information. This speeds up learning as well.

@Demolishun covered it really well

Your boss is too intelligent or too rude

Ask your boss if they saw a negative impact with slow learning. I would prefer you learn good and solid to being a quick and error-prone learner

@AtuM I'm looking for another job, wish me luck man.

Sounds like a very toxic way to communicate "we can't afford a raise".

@AtuM No he's just a dickhead, even when I handle things well he has an excuse to put me down, oh well...that was not such a difficult task, don't you think you will have the same level of preparation next time.

"I admit that I'm a slow learner. It took me x years to learn that I should leave this job."