Interuptions

I'd love to be a full-time author.  To write for a living. I've really enjoyed the process. I've often wondered what it might be like.  I know that I can sit for a few hours and write if I get the opportunity. Whilst waiting for my daughter to take part in a chess tournament a week ago, I was able to rattle off two chapters of Realms Unravelled. What was great was that I sat there undisturbed for at least forty-five minutes at a time. It's not often I get that sort of time, and I did wonder if that's what full-time authors experience. They hide themselves away and write. It's not a luxury I normally have. Holding down a day job and being the father of two, free time is scarce.  I've mentioned how I write while waiting for various extra-curricular activities to end. I also try to grab ten or fifteen minutes at the weekend if everyone is busy. One of the biggest challenges that I have to overcome, is interruptions.  For all four books, I have been constantly interrupted while in the middle of a sentence.  Often, the disruption has meant I've had to go back and finish the sentence a few days later.  I think it's a skill that I can retain, that chain of thought, for a few days and pick it back up without an issue.  The only time I really got annoyed at an interruption was this week. I was writing a chapter in Realms Unravelled. A scene was particularly poignant and a real turning point in the book. One that may upset and surprise the readers. I had to break off mid-way through. All I could think about for the next few hours was getting back and finishing it off.
Is that what mainstream authors experience? I doubt it.  If that is your job, surely the interruptions are fewer.