At times, Telemachus was indeed easy to forget.
After Odysseus's return home, it was as if a heavy burden that the young man had carried for twenty years had been lifted from him. Previously, he had been a sight to behold, looking haggard, somewhat reserved, and sad. However, things quickly changed as the prince regained his spirit, became stronger and wiser, and finally looked like a true man.
But even men can dream.
Everyone knew that Telemachus wanted to become famous not only for being the son of Odysseus, but also for conquering new heights, protecting people, and defeating various monsters. And sometimes he was so deep in his thoughts that it was impossible to get him out.
And right now, this boy is galloping through the courtyard of the palace with a sword at the ready, imagining how he is fighting a Hydra. In fact, it's incredibly funny - especially when you know what his reaction will be when he finally notices you.