If I write a sentence in my editor, then change a preference setting, then click 'undo', should that undo my typing or the preference change? I feel like a glob

If I write a sentence in my editor, then change a preference setting, then click 'undo', should that undo my typing or the preference change? I feel like a global 'undo last action' would be very confusing, but how else would you get rid of 'cancel' everywhere?