Tonight in Prague though was maybe a cold dose of reality.
Mount returned to pre-season training at Chelsea in July with Frank Lampard only just appointed as the new manager.
The same man who had seen him score eight goals under his command in the Championship last season on loan at Derby.
Lampard from that year at Derby knew all about the youngster and insisted straight away Mount would be part of his first team plans at Chelsea. And he was as good as his word.
Gareth Southgate knew Mount as well from his progress though the England youth ranks, and swiftly there were two England substitute appearances. Then last night, after four goals in eight Premier League games, came a full England debut for the 20-year-old.
Such had been the Hampshire boy’s spritely club form, he kept an experienced player like Ross Barkley – and a £58million new signing in Christian Pulisic out of the team.
And as of last night, there was Barkley on the bench again and Mount in the starting line-up – this time with England.
Southgate, who had been impressed with Mount in training this week, said in the build up to last night’s game: “What do I think of Mason?
“Exactly what I thought of him when I saw him at 16 playing for our U16s. He’s a quality player, an intelligent footballer, presses well, has a real eye for goal, and good quality. Nothing I’ve seen surprises me at all.”
So far, Mount, starting alongside best friend and former Chelsea academy player Declan Rice, had taken it all in his stride.
But for much of this match the game passed Mount by. He started promisingly – his pass was flicked on by Harry Kane to Raheem Sterling which led to the penalty which the England skipper tucked away to give his side the lead.
But within four minutes the lively Czechs were level, as England’s wobbly defence let them down again and Jakub Brabec levelled.
Mount only touched the ball five times in the first quarter of the game, despite some energetic chasing and closing down.
But in fairness he was not playing on the left, as he does with his club – instead for some reason pushed into an advanced role for the first 45 torrid minutes.
Too often, Mount found himself starved of the ball, despite making some good runs. He was not alone in struggling to make an impact – England, after their bright start, were ragged and disorganised.
After half-time, Southgate tinkered with his formation and Mount looked happier on the left of a midfield three. His control was good and there were a couple of typically accurate crosses.
This one though is going to have to be marked down as a learning experience for the young Chelsea player. Another little step along the way.
With 18 minutes left up came the board – and on came Barkley, for Mount. It had been a hard night for the 20-year-old. Whether on this evidence he has edged ahead of his team-mate on the international stage is doubtful.
Even in stratospheric climbs there are blips.