On the whole mindset of a champ thing, one of my favourite sporting quotes comes from 5 times world motorbike champion Mick Doohan.
When fellow Australian bike rider Casey Stoner was competing in the lower classes he was always one of the fastest riders, but after taking the lead early in a race he'd more often than not drop the bike pushing too hard for the win.
When Doohan was asked about this sad state of affairs, he quickly replied it wasn't a problem as you can teach someone to stay on a bike but you can't teach them how to "be fast". Stoner has gone on to win two world championships and has ridden bikes fast that no one else can.
With tennis we can teach my son to be more consistent and improve his footwork and technique. What I can't as easily give him is that desire to compete and win. Him being the one always at me to go for a hit so he can improve. Always at me about what tournaments are coming up and how many events he can enter.
Like I found out as a junior, at some point his ambition will outweight his talent and he will find his own level. At which point I hope, unlike me, he stays with tennis and accepts that improvement will be slower but he can still enjoy the game.