I'm old school ... ex military, bush flying (various singles and light piston twins), corporate (small turbo props) and then the 707. Transition to the 707 was a big jump for me but not impossible to overcome in a relatively short period of time. Flew 'heavies' for seven years before landing a 744 position.
The transition to glass was a challenge but again, was overcome with time. 744 > 330 > 777. The 330 transition was another challenge ...
The training environment in which one finds themselves is all important, as is the age of the pilot. The youngsters soak it up but the older one is, the harder it becomes. I've been in that position and seen others in it.
EK training is of a very high standard. There is very little spoon feeding. One has to be 'on it' from the start and the pressure doesn't stop until one is checked out to the line. EK is not an outfit where it pays to rest upon one's laurels either.
Recurrent sim is always just around the corner and many fall foul of the system if their discipline, initiative and perseverance has waned. It's called resilience here, and you'd better bring a lot of it with you.
One is crucified by the workload but at the same time given no slack because of it.
As I mentioned earlier, the training standard is high and one needs to not only ingest information as if distributed by a fire hose, but retain it ... all of it, all the time.
One's experience, language skills, technical aptitude, age and ability to withstand an unpleasantly high level of stress will either hinder or help.
Five sectors a day in a TP, or 15 000 hours on heavy jets, everybody starts here at 'ground zero'. Your previous life means very little. All it will do is help you to cope, or not, as the case may be.