Learn Swedish: Han är inåtvänd och trivs hemma. - He is introverted and enjoys being at home.

It literally translates to "inward-turned." It is a compound of the directional word inåt (inwards) and vänd (turned, the past participle of vända). It is the most common Swedish term for "introverted."

Since this lesson covers reflexive verbs, why doesn't trivs use a reflexive pronoun like sig to mean "enjoys himself"?

The verb trivs belongs to a group called deponent verbs (or s-verbs). These verbs always end in -s and have an active meaning. Unlike reflexive verbs that require a separate pronoun (like bry sig om), trivs has that self-contained meaning baked right into its -s ending.

Could I use trivs to say he enjoys a good book or a meal?

No, trivas is specifically used for feeling comfortable, contented, or thriving in a particular environment, living situation, or company. To say someone enjoys an object or an activity, you would use verbs like njuta av, gilla, or tycka om.

Just as a quick refresher, why do we use hemma here instead of hem?

The word hemma indicates a static location ("at home"), which fits perfectly with the verb trivs because it describes a state of being in an environment. You only use hem when there is motion towards a destination, such as Han går hem (He is walking home).