I liked it, I was hungry (mi-a plăcut, mi-a fost foame)

I liked it: mi-a plăcut

In îmi place, the thing you like is the subject and you are the to me pronoun. The past keeps that shape: the pronoun hooks onto the auxiliary — îmi + a = mi-a — and the verb becomes plăcut. The auxiliary agrees with the thing liked: mi-a plăcut (one thing), mi-au plăcut (several).

I was hungry: mi-a fost foame

Mi-e foame (I'm hungry) is îmi + e. In the past, e becomes a fost: mi-a fost foame, ți-a fost frig, i-a fost sete.