It appears my cat has learned how to open doors, and now I have
to lock them with a key. (The doors have the L-shaped horizontal
handles, not the round knobs, of course.)

The first sign came when I found the door to the patio open
twice in one week - being ABSOLUTELY POSITIVE that I have shut
them the night before.

Tonight, after looking for the beast around 9 PM to feed him, I
gave up, and went back inside closing the doors, planning to
return in an hour or two. Half an hour later the cat was at my
desk mewing for food. I came downstairs to the kitchen and one
of the doors as open about 10 inches. I HAD left it CLOSED.

I noticed several times that as opposed to MOST cats (AFAIK),
when "faced" with a slightly ajar door, my cat does not stare at
it helplessly and meow, but raises himself on his rear legs and
pushes it open. I found that quite impressive on itself.

I find the fact he has figured out that pressing on the L-shaped
handle will open the closed door AND can do it from BOTH sides
of the door (there are ledges right next, outside AND inside),
quite amazing.

Is this more common than I thought or is this cat from outer
space?