Readers differ on a small question with large consequences: is the Hermit's light for himself, or for someone else?
Read the first way, the card is inward. It counsels withdrawal, patience, the deliberate reduction of input, and a search that has to be conducted alone because nobody else is standing where the querent is standing. This is the dominant modern reading, and it maps easily onto contemporary ideas about retreat, therapy and self-knowledge.
Read the second way, the card is a beacon. The old man is not looking for anything; he is standing where he can be seen, holding up a light for people still climbing. On this reading the card asks whether the querent is being sought rather than seeking, and whether they have knowledge somebody else needs. Waite's own description leans towards the beacon, and Golden Dawn material treats the figure as an adept.
Neither reading is a reversal of the other and a good reader will usually try both against the spread. Waite's reversed meanings for this card run to concealment, unwarranted caution and isolation that has stopped being productive, and those are genuinely useful senses. Readers who work without reversals find them by asking how long the withdrawal has been going on, which the surrounding cards will normally say.
The one reading to be careful of is the flattering one. Solitude in this card is not automatically wisdom. It is sometimes just solitude, and the tradition is honest enough about that to have kept the harsher meanings in print for a century.