And even though my dog is perfectly house trained, she will occasionally get sick, etc.Moral: Pets are pets.  

Occasionally I will have a tenant move out in less than a year, maybe 10% of the time.  

We do have the occasional case of accidentally building on your neighbors land. 

The only downside is that you occasionally have to raise rents on your friends.

Occasionally there are some that didn't do their homework and try to get me to pay them but they quickly learn that I am willing to loose money to get them out.

Occasional freelance income as well.

We'd occasionally get roof rats and would have to bait for them. 

Our "all-stars" receive special benefits such as having their unit upgraded first when we do upgrades, special requests are more often accommodated, and occasionally we give them a special thank you gift.

You'll also get the occasional group of drunk students walking by as they are going from bar to bar, and the ambulances also use this street, so if you need a quiet place, you might want to look somewhere else. 

Way less maintenance.If it was property I was living on, I'd rather have my own septic/well.With the well, it has to be tested occasionally, and the water may have to be treated.