Level 6 Referee
I have never been at a high level, but have sort of experienced this. I had a County Cup game where neither team knew me. When chatting to the managers pre-match I mentioned what games I 'd done and they assumed I were a much higher level than I was (was a 6, they assumed 4/3). That game was an absolute breeze, with both teams respecting everything I were saying/giving, and plaudits after the match including 'wish we could have refs like you every week'. It gave me great confidence on the pitch too, which helped in turn. I might just go to different leagues weekly to try it again! @afronaut81 I believe that was a team from your league..An SG ref would almost certainly breeze even the most difficult of grass roots game. I never made it that high, but after I quit L3 I went back to Sunday mornings and found it was an absolute doddle compared to when I'd previously done that level. I went months without issuing a single card, think it was 15 or 16 games from memory, all at Hackney Marshes. Two reasons for that, one is obvious in that I was vastly more experienced than the previous times, but more importantly the players quickly worked out that I'd been at a much higher level, trusted me and just let me get on with it. And I did just that, staying out of the way unless I had to get involved. The only thing they didn't like was my talking to them, at least initially. "Ref, why are you telling me not to foul him?" "Were you going to foul him?". "Probably", "OK, so I've saved you a yellow card then yes?", "Fair enough ref" ... . I know other referees who have stepped back down who tell similar stories.
When my card less run ended it of course was spectacularly with a total nightmare of a game with mass cons, reds, and managers sent the (very) long walk back to the changing rooms. Even then though I managed it fine, and had the same thing happened back when I was L7 or L6 I'd have been a right mess.
An L7 going into the middle of a PL game would be immensely more difficult. The pressure in front of tens of thousands of people is likely to play an effect on everyone no matter how good they are, and it would be pretty much impossible to adjust to the pace of the game jumping straight from L7 to SG1. Worst of all though the players would seize on it big style and would be right on the referee's back at every decision, but the smarter ones would have been encouraging him beforehand to try and sway any decisions their way. Whilst it is generally acknowledged that players aren't always the sharpest tool in the box, the higher you go the smarter they get, not necessarily their IQ but certainly they are more mentally and game smart.