Whenever I have a brain fart, my 12 year old daughter loudly and sarcastically thanks Thomas. Words can't express how much I appreciate her sense of humor.
ScienceClic on Youtube has amazing videos on this topic as does Veritasium. Einstein's happiest thought helps with understanding this. He thought that there would be no discernible difference between what a man felt while falling off a ladder (let's not factor in air resistance) and what a person in 0g space felt.
We are actually "accelerating" upwards at a constant rate that is equal to what we feel and many think of as gravity. This is because spacetime is curved by the mass of the earth.
Think of a grid being distorted or squeezed / pinched. The distortion pinching is "gravity". Everything in the grid still travels in a straight path relative tot he lines on the grid but since the [spacetime] grid is pinched, it looks as if it is not on a straight path.
Dear lord.