Does what we say matter?

you stand on the shore of the lake and look at the calm wave surface.

suddenly you hear a splash and see circles scattering across the surface of the water.

someone has thrown a pebble into the pond.

you bend over and pick up a small pebble, swing it around and throw it into the water.

the circles on the water. they spread out and overlap each other.

someone on the other side of the lake now knows that you exist.

Yes.
Everything we say, everything we think matters.
Our words affect us, and others.
Our thoughts affect us, affect our words and actions, and therefore others.

Pick whatever is positive and suits your frame of mind.