Ahem... My personal history in this regard is none too admirable. Let's just say I haven't been a fiscally disciplined cyclist or photographer/birder over the years. Your friend who coughed up $2K on bike gear looks like a model of restraint to me.
Many of us on this forum find ourselves never richer, never healthier and never with more free time than just after retirement. The temptation to "blow that dough" on a new hobby can be overwhelming.
(Un)fortunately this has happened to me.
I started mountain biking in earnest after FIRE. At first I got an "average" $3k full suspense bike, but the more I rode, the more I learned about "better" equipment, riding style, and seeing other riders with better equipment, and allowed myself to be drawn into the endless cycle of "upgrades."
I ended up buying two more top-of-the-line cross country carbon hardtail mountain bikes, one for trail riding and one for more grave/cross country riding. That's $16,000. Then every year new equipment comes out and I've got to have the latest/lightest/best stuff, so I upgrade forks, wheels, handle bars, etc., etc.
My latest upgrade is a new fork for one of my carbon hardtails. I spent $900 for the fork which drops my bike weight to a feathery 19 lbs. But that's not good enough as I've gotten bitten by the "weight weenie" bug and am looking at a brand new pair of $3000 custom-built carbon wheels that would drop another 250 grams from my bike weight.
I figured that I've spent almost $35k on bikes and related gears and clothes since FIRE. I've got pro-level gears but I don't even race. Sometimes I look at the stuff that I've bought and just kind of shake my head. The saving grace is that I really enjoy riding. I ride 5-6 days a week, and try to hit 4k miles distance/500k feet elevation gain every year. I figure that if I enjoy the sports and have the means, I might as well get the best stuff money can buy to make my riding experience as fun and rewarding as possible.
And yeah, I'm probably going to get those $3000 custom-built carbon wheels for the bike