Good advice as ever.
I'd add to it that you shouldn't listen to people saying you can't do it or the good old days are gone or it's not like it was.
Rory off here said numerous times to me and others for that matter, to "just work harder than everyone else" and it's true. Instead of moaning about something not happening, work harder etc. If you have your own successful business then you no doubt have this mentality anyway.
There are a couple of sayings I like.
One from Gary Player, the American Golfer; The harder I practice, the luckier I get"
The other, supposedly George Bernard Shaw; "People who say it cannot be done should not interrupt those who are doing it"
Good luck.