Every human being whose mind is not debauched, will be willing to give all that he has to get knowledge.

Wanting to know things is close to a default setting, and when it disappears something has usually worn it down rather than it never having been there. Fatigue does this, so does constant noise, so does a job that punishes curiosity. The appetite tends to come back when conditions allow, which is a more hopeful diagnosis than deciding you have simply stopped caring.

If you have not been curious about anything lately, treat it as a symptom rather than a character trait. Ask what has been draining the attention. Then give one genuine interest an unhurried hour and see whether it stirs.