Why do cats like to roam even if they fixed?

I have a 1 year old male cat "Jesse" whom I have had since he was six weeks old. He loves to go out side any chance he gets. He has been gone two days now. He likes to roam around the neighborhood even though he is neutered. Jesse will usually come back to eat several times daily, but every so often he stays away a longer period of time, maybe a day or overnight. I try to keep him indoors, however, he manages to escape occasionally when someone opens the door. Sometimes I wonder if someone else is taking care of him thinking he is their cat. He is friendly, affectioate, and I think, likes to play with some of the other neighborhood cats. I just hope nothing bad has happened to him. I am always afraid that one day he will not return at all. What are your thoughts about Jesse's behavior? Please pray that Jesse returns to us(for good, never to leave again!) in good health and unharmed(I hope he didn't get hit by a car.) Thank-you in advance for your thoughts, prayers and sugestions!

What do you expect him to do- just sit by the door?
Of course he's going to roam around- there are interesting smells, bugs to chase, animals to investigate...

I'd work on training him not to bolt, and training other folks in your household to be more attentive while going in and out. It's a dangerous world out there for a kittie.

I hope Jesse returns unharmed. When he does you may want to consider harness training him so you can take him outside safely.

Heck if I know. Our barn cats don't really roam that much - they may go into the fields but never more then about 1/2 mile away as far as I can tell.

Ling would LOVE to go outside, but we are not letting her out.

Thanks for your encouraging words everyone.