I’ve had it (around age 17). It’s also called “Mono” in the US, and “Glandular Fever” here in Australia.
I’m 38 now and I’m sure it still contributes to added fatigue when I get run down and sick. Took about 12 months to get over to the point I could resume normal exercise and activities.
Best advice - don’t overdo it. Listen to your body very acutely. It can turn into chronic fatigue if you’re not careful.