It may only be coincidence that you didn’t follow procedure.
As Craig says, try spare key.
Has your key lost the transducer that is usually in the bottom corner of the plastic part next to the metal key itself.
I believe there is a sensor ring in the steering column surrounding the key hole. That picks up the presence of the key when inserted but is known to be troublesome on some cars. Hold the key flat against the key hole for a few seconds, then insert key and try to start within 30 seconds.
