Is it bad to not care if a person you're in a relationship with is smart or not?

I broke up with by GF 1 month in because i think she will outgrow me and get bored of me because she is smarter. I was the kind one and that's what she liked about me.
Did i overanalyze and fucked myself up?

The only time intelligence is a factor in a relationship is if the person thinks that money and credit cards are infinite.

It’s not