Wooden

 Te duchabas mil veces, te ponías

fijador en el pelo, y la esperabas

impaciente en la puerta del colegio.

Luego ibais a sentaros a aquel banco

del bulevar, o a casa de tus padres.

Pasó el tiempo. La magia de la cita

te llenó la cabeza de ilusiones. 

"Estoy enamorado" comentabas, 

orgulloso y feliz, a tus amigos. 

Let's look at this again.  It scans perfectly well as 11-syllables lines. The first line, for example, has accents on 3, 6, and 10, a perfectly acceptable combination:  

Te duCHAbas mil VEces, te POnías... 

Why, then, does it sound so wooden?  Maybe because it has a prose feel. The lines are enjambed (nothing wrong with that) but the enjambment isn't really doing anything. It would be fine as a paragraph of prose:  

Te duchabas mil veces, te ponías fijador en el pelo, y la esperabas impaciente en la puerta del colegio. Luego ibais a sentaros a aquel banco del bulevar, o a casa de tus padres. Pasó el tiempo. La magia de la cita te llenó la cabeza de ilusiones. "Estoy enamorado" comentabas, orgulloso y feliz, a tus amigos. 

But it isn't well written prose. Even literary prose, as in a typical novel, has more metaphors or other tropes than this, is less pedestrian. Has at least some wit or edge to it. It is the banality of what the words are saying and the arbitrariness of the phrasing that makes the poetry so unmusical, not the actual sounds of the words, though I would say "Luego ibais a sentaros a aquel banco" is unmelodious, for example. 

Here's a slightly better poet, no genius, but one who at least understands you have to try a little harder: 

AHORA, juntos, vivimos la hermosura

de esta tarde de junio,

el fulgor de las horas en que nos entregamos

al conocimiento de la verdad del amor,

a la gran llamarada del encuentro.

It's still cliché-ridden, but it's poetic cliché, not mere prosaic cliché. We understand the "el fulgor de las horas" [the radiance of the hours] is more "poetic" than "la magia de la cita." These poets pride themselves on being easy to understand. We understand that the beauty of the June afternoon is beautiful, like the knowledge of truth of love or the great flame of the encounter. 

I was often criticized as being dogmatic for not liking this sort of thing.