If you haven't read part one or part two, you may want to take a look at them. You can read them in any order, so feel free to finish this post and then look at the others.
OK, now let's look at our example sentences again, but this time using olvidar.
Did you go to the bank? - No, olvidé.
Olvidé las llaves - I forgot the keys
Olvidé traer las llaves - I forgot to bring the keys
Lo olvidé hace mucho (tiempo) - I forgot about him a long ago
Olvidé llamarte - I forgot to call you
Olvidé el libro - I forgot the book
If you noticed, using olvidar is a tad bit easier than using olvidarse, because we don't have to worry about remembering whether or not to use that pesky "de". And conjugating olvidar is much simpler because it's not reflexive.
So now we have 3 different ways to say the same thing - I forgot [something] or I forgot [to do something].
In the next post, I'm going to place everything side-by-side, so we can have a nice cross reference.
¡Hasta la proxima!
***NOTE: There are 4 parts to this subject, and you can see them all by clicking here