LOL. Sorry for laughing but when you know, you know.
I could have been bitter but I gave up at 10 submissions rejected from various sources. (small presses, a few agents) I'd heard the mantras that Robert Silverberg (and Larry Niven and even Stephen King) wallpapered their offices with rejection notes. That for some famous authors it was a decade or more of rejection before they made it through the crack in the door. That John Grisham started out selling his books from his car trunk on street corners because nobody gave him the time of day.
But all of those blurbs made it less and less likely I was going to keep shoving at the fortress wall around the publishers, guarded by agent gatekeepers. I don't love rejection, and have gotten too much from other arenas to enjoy another round in the literary world. After learning that publishers don't accept manuscripts, or even first chapters, or even query letters, that they only work through agents, and the agents, again, only accept query letters when they are in the mood to, or are open for submissions because they happen to be hungry, that I sat back and waited until self publishing became a viable alternative.
Especially when I learned that an agent may receive 100 query letters in a week, and select one to ask for more info, and out of 10 with a first chapter, they might select 1 for a mss, that out of 1000 query letters from agents in a month, a jr editor might select 1-5 for a first chapter, and out of 10 first chapters they might ask for ONE mss, and out of 10 mss, they might bring ONE query letter to a monthly editor's meeting. That out of 10 proposed pitches from editors on staff, a house might select one to publish a month (a bigger house might publish more):
Thomas Nelson: 250/yr
Zondervan: 300/yr
MacMillan: 250/yr
Simon and Schuster: 2000/yr
Random House: 15,000/yr
Still, for the bigger companies, the sheer volume you are pitted against ramps up exponentially. Odds are astronomical, and those are simply random odds. Your book may be jaw dropping, your first chapter riveting, your opening page mesmerizing, your elevator pitch tantalizing, and yet... you still go into a waste bin because somebody is too busy, too bored, already committed to somebody else, etc. If any of those things (pitch, first page, etc) was in the slightest bit not a superstar to your agent or jr editor, you are already out. Even if they are perfect, odds are not good.
Sorry, but I had a day job I was good at and happy with, that paid well and kept us in diapers and food, so I was fine with writing as a hobby, or a calling that was on God's nickel, and His timing, not mine. If I had NOT taken the self-pub route, I would be a decade older inside, bitter and closed off. And still not published. So the cost-benefit analysis says it was a good decision to indie my books.
Can't say I haven't taken the reins back too often, or that I don't pine away about lack of sales now that I'm published, Or at how marketing is expensive and barely nets a profit. But I can say I avoided a lot of baggage from skipping the dance with agents and publishers after the first waltz. I'm happy to let them snub other dance partners without giving them another opportunity to ignore me.