Such as one's childhood, which doesn't have a beginning or really an end,
but it's really more important to think about the period in the middle.
Descriptions in the past are usually expressed with the imperfect
because starting and ending points are not the focus of what you're saying.
Descriptions are about middles.
You can use the imperfect to set the stage for
other more dramatic actions that took place or were taking place.
For instance, if I say [FOREIGN], translated, I was cleaning
my house and listening to music on
the radio when someone knocked at the door.
In this case, the cleaning the house, the listening to the music set the stage for
the action of someone who came and knocked on the door.
The imperfect tense endings are for a r verbs,
aba and for ir verbs, ia respectively.
Verbs that express states tend to be in the imperfect, when talking in the past.
For example, tenia un dolor de cabeza, I had a headache.
The importance is the middle of the having the headache.
Me sentia mal, I was feeling bad.
Again the importance is the middle of the feeling bad.
Estaba triste, I was sad.
Sabía mucho, I knew a lot.
You not referring to the end or the beginning of knowing, it's the middle.
Me hacía falta café, I needed a coffee.