But, that doesn't stop the fact that I do like people, I like organizing parties (or rather I don't particularly like the organizing but I like the result of having organized parties and having close friends) at my place and regularly invite friends. It's just that after that I'm exhausted and I need some alone time to recover. So being an introvert doesn't imply that you shouldn't make effort to reach out to people or that you won't enjoy being with others. It just means that having some alone time is necessary to recover.
That's the Big 5 meaning, which has some scientific backing. The other one that basically just means social/shy comes from Myers-Briggs, which while popular isn't based on anything and is pretty much just pseudoscience.
There are people whose feelings about it vary, but there are also people whose feelings about it are consistent but they do it anyway, and that sometimes gets mistaken for variability.
I taught at a community college for a few years and have spoken at conferences. Those engagements are immensely enjoyable and energizing to me because they're performances. The roles of the audience and presenter are clear. I do my thing and the audience does theirs. I get that energy and enjoyment (a ton more of it, actually) performing live music. I walk off a stage jazzed. It's a wonderful high.
The dinner party scenario is absorbs energy. It's not necessarily less enjoyable than performing, but because it's peer-to-peer there's so much more protocol, nuance, and thought than performing. Even if I'm talking with people I know well I don't walk away energized. With people who are new to me it's a lot of work. Like anything it has come easier w/ practice.
I'm here to tell you that you are most certainly wrong on this point. People exist that view this kind of thinking as so bafflingly alien that they can't understand how someone would think it.
Social interactions require enormous expenditure of energy for me. They are not pleasant or energizing, they are rituals that must be accomplished to help me blend into a world that is not designed for me. I am most assuredly not being convinced of this by books I have read.
Some people who are actually somewhat more on the introvert side but force themselves to socialize, think that it's in fact supposed to be a struggle, for everyone, and everyone who seems to enjoy it is to some degree pretending, and is more diligent in putting up with the discomfort, so it's a character quality trait how much you get your act together and endure socialization.
It's like hating blue cheese or certain vegetables or the taste of niche foods. But in fact some people do enjoy the food, and don't eat veggies because they must or have great discipline. In fact this is also true of exercise. It is something that people do enjoy, the pump, the endorphins etc. (Usually it does take getting to a baseline fitness level to make it enjoyable, so it's not a static personality trait.) Similarly with public speaking or working with people all day etc. Some people truly love it and look forward to it. It's not only that they are tough and endure the suffering better. They do like it.