When I was 20-something, I would have to you I was doing everything I could to make it as a professional drummer. I would have said I was giving 110% and sacrificing everything.
In retrospect, I was giving maybe 70-80%.
Being friends with and having spent a lot of time around actual professional drummers I can see now:
I was never into staying up all night (or was getting up early?) to transcribe and chart out songs for a band you might only do one gig with. I wanted to know there was a chance of many gigs if I was going to do that work. But real pros have no trouble doing that. So what if you're just subbing for one show one time, you put the work in.
I didn't buy into continuing to practice 8 hours a day long after graduating PIT (where I did, in fact, practice 8-10 hours a day). Sure, I still practiced often, took lessons, etc, but not nearly enough.
I was worried about money, so I always had some sort of side job, mostly because I liked sleeping in my own bed in my own room. I didn't embrace sleeping in the rehearsal hall or pilling a bunch of people into a small space just to keep costs down. (See stories of many bands who all slept in their rehearsal room or in one band house, or in the van). Sure, I didn't always have a nice apartment, but I could have sacrificed more. (
As much as I did network, I didn't network enough. As Bermuda will say "it's not who you know, it's who knows you". I was good at getting to know people, but I was terrible at letting people know me. Hence, they didn't think to call me. (mind you, this was all pre-social media).
I very quickly really grew to dislike playing music I didn't 100% enjoy, which meant I didn't pursue gigs that might have lead to better gigs. Nor did I chase gigs that might have gone somewhere. By age 25, I was sick and tired of playing Mustang Sallly 3-4 times a week, every week, and didn't want to do anything like that again. I should have kept a more open mind.
I spent too much time looking for the perfect bands to be in, and not realizing that just playing in bands is the best exposure to being in better bands.