The first time my dwarf hamster got out of his cage by himself (realized its open) he was really dramatic and hyperactive. Then he ran into his house...i closed the cage and then he went all mad with running, biting, digging everywhere around the cage and trying to get out. I was really unhappy to watch him go all crazy like that, but on the other side i dont know if he is not maybe doing the same thing around 5am when i hear his wheel but just cant be able to wake up and watch him...
Anyway i think that your hamster recognizes you and that is great
. Also i think they just love exploring so when he realized that sometimes he gets food and sometimes he gets walks when youre around...well he sure wants to get your attention now
If he has toys and space in his cage i wouldnt worry that much and just play with him as often as i can
.... but im just a beginner sorry