In German "to remember" is translated as "sich erinnern", it is used as a reflexive verb. That's where the "mich" comes from.
ich erinnere mich
du erinnerst dich
er/sie/es erinnert sich
wir erinnern uns
ihr erinnert euch
sie erinnern sich
Please note that there's a difference to "jemanden an etwas erinnern" (to remind so. to/of), this one's not used reflexive. (Unfortunately, nowadays even lots of native speakers don't use the reflexive form where it should be used.)