For the new travel trailer owners, things that happen to me.

Here's a (probably only partial) list of all the things I have forgotten at one time or another when pulling a TT:
left the step down.
did not lock the refrigerator door.
did not turn off the water heater gas valve.
left the fresh water fill cap off.
left the home-made awning sun-shield on.
did not lock the entry door.
left the water pump on.

I keep telling myself if I just take my time and pay attention I won't forget any of this stuff, but I should just break down and make an actual check list.