So, you did something that made you feel smarter. To make sure the effect is real, you could take an IQ test, assuming you took one in the past, and compare the numbers.

I think it is relatively common to have a feeling of becoming smarter without actually being so. The change of mood already can move you from "ignores things" to "observes things and wonders about details". Learning something gives you domain-specific knowledge. Abstract mumbo-jumbo can make you feel like you understand the deep truths about the world. Good speakers know how to induce these feelings in their audience. Crackpots can induce them in themselves.

But the feeling doesn't necessarily correspond to reality. In fact it is often the other way round, e.g. when people are on drugs, their critical thinking turns off, and they believe themselves to be super-smart. Only, when they write down their supreme wisdom, it turns out to be garbage when they get sober. Your hormones can have similar effect, e.g. if you are super excited about something.

Try doing actual tasks that someone else gave you, and see whether you actually became better according to that other person's criteria. Anything else is just potentially deluding yourself.