I suppose you can stick with either M/T or A/T and become a pro in either one. It's transitioning between the two that might pose a minor problem.
Me for example...... I have no problems transitioning from A/T to M/T. The higher rpm noise often alerts me it's time to press the clutch and shift.
But, going from M/T to A/T...... I have a tendency to look for a clutch. Guess which pedal comes closest to a clutch in an A/T.

It takes a few hours of alert driving before I adjust completely. Most of the time, I'm fine. But, when I'm distracted (like with a nagging wife), it's scary when I do mistake the brake pedal for a clutch. Thank goodness for seatbelts.