I did the same thing Id spend at least 15-20min after each range trip looking for my brass. It was kinda like just having money laying on the ground for everyone to take. Or you get those ones at the public ranges that will try an take it anyway . But since I have my own range now its a lot nicer to leave it lay for a day or two an not have to worry about picking it up right away cause I know it will still be there. But I feel your pain OP been there many times spending as much or a little more time looking for brass then actually shooting.
I almost cant stand to leave brass at the range. There is usually more there than I can get. I pick up mine and what I see. I cant seem to stop. I love getting as much as I can carry. But the sacrifice is not getting enough practice. I love shooting. I equally love reloading too.
I normally pick mine up after a mag or 2, the time makes for a short break. I will normally do a walk around before/after my range time looking for strays. <-- All that at public range. If @ private, wait until emd of shoot, or pick it up randomly during BS sessions.
Got blessed Friday, very nice fellow gave me all of his spent 9mm brass. ~150 or so.
I spend a pretty fair amount of time picking up brass. My wife likes to shoot as much as I do and she is very good at finding brass...I would be lost without her lol. I collected brass years before I started reloading.
I used to spend a bunch of time hunting for spent brass. Then I dug into my garage for an old tarp and started including it in my range supplies. Now, whenever I shoot, I just stand left of the tarp and I let my brass fall on it.
I now spend more time shooting and a whole lot less time scouring for spend brass.
Let's just say that I don't leave much behind even when I'm in a hurry...