You have a point except for my life isn't on the lines. Like I said, everyone starts somewhere. 
I think that, as I read back through the thread, most people did offer the lens advice you were seeking. But they also offered the opinion on the first-time-wedding-shooter experience.
Indeed everyone does start somewhere. But "somewhere" could be by being an assistant or second shooter for another photographer. I'll offer an example.
I don't do weddings anymore, but I used to. I worked for a studio starting as an apprentice when I was 15. I've done somewhere in the neighborhood of 500 weddings (I never kept careful count... but as I reflect back on the years I realize the number is very close to 500.) When you do that many weddings you get experience on your side. My boss was also professionally trained. He didn't plunge in either but worked as an assistant to other photographer's before him ... back when he was much younger -- just as he was now showing me the ropes back when I was younger.
We knew the flow of the wedding. We knew the repertoire of shots that needed to be captured. We knew the best techniques to capture
each of those shots. But we also always anticipated (based on knowing the flow of the event) which shot was coming next and what settings would be best for taking that type of shot. Those settings were dialed into the camera even
before we approached the subject.
For example... suppose it's time for the bridal party to begin the dance. We'll need to photograph the bride & groom dance as well as each of the couples in the party as they are introduced.
What's going through my mind at this moment is:
- I'm planning to take a half-shot (waist up) of the couple dancing closely.
- I'll be standing about 6' away when I take the shot.
- The lights will be dim and I'll need flash.
- Due to light fall-off I don't want a severely underexposed background so I'll want to set a shutter speed which "drags the shutter" to collect more ambient light. This may put me down in the 1/50th second speed (or somewhere near that).
- A slow shutter has a strong potential for motion blur and I don't want that... SO...
- I'll approach each couple and gently tap their hands (which they're holding as they dance close) and guide them to face the camera ... but ALSO I'll ask them to pause and hold for just a moment while I take the shot.
- I'll thank them and move on to the next couple.
This isn't all of it... I may or may not be able to "bounce" the flash... that depends on if the ceiling is white and the ceiling height. If my flash is manual instead of TTL then I'll need to vary the aperture to control the light from the flash. With my equipment, I'd pre-focus the camera to 6' and set the aperture to f/16 for that distance.
This technique results in beautiful blur-free shots with very nice balanced lighting, a well-focused subject and pleasant background. The technique provides me with
consistent results. That consistency is key (especially when I'm shooting film and I can't review the shot after taking it. I have to be able to bank on the fact that my technique worked and I won't be in for any unpleasant surprises.)
Now here's my point... I wish I could say I came up with this and take credit for it. But I didn't. I know to do this, because I didn't jump in and start shooting weddings hoping for the best. I apprenticed with a professional photographer starting at a young age. I didn't hold the camera... t hauled the gear, held and moved the lights, reloaded the film magazines, etc. But most importantly... I watched and learned from my boss. He didn't always have time to explain what he was doing. Often when he was done and we were driving from the wedding to the reception ... or just taking a break at the reception... he'd explain what he was doing and why.
Consequently, I'm not a nervous wreck when shooting a wedding because I've been well-trained to know what to expect and always anticipate what should be coming up next, what to dial-in as my exposure pre-sets (sure... I might need to adjust, but when you've done hundreds of weddings you get pretty good at anticipating what works best), and what techniques work best to capture the shot. These techniques get "burned into your brain" like muscle-memory. These photographers follow them almost instinctively. (This is why you want to pay $3000 for a photographer instead of $300. The expensive photographer with the impressive portfolio is going to get consistent results. The $300 photographer isn't relying on their wedding photography business in order to eat. The $3000 photographer is.)
There's a lot more. I just used one example (capturing bridal party dance photos). Someone who has never shot a wedding before is more likely to just take the photos and let the camera figure it out. They "wing it". More than the likely, the resulting photos will
look like they decided to "wing it".
You may, and probably will, shoot your friend's wedding anyway. But it's not that everyone here is just trying to be a "Negative Nancy" about what
may happen. The collective observational experience that so many of us here tend to witness is that the results from the "first wedding" photography tends to come in far below the initial expectations of the bride and the friend shooting the wedding. THEN it becomes a "I wish I had that known that." and "I wish I had done ___ when getting this shot." Then the "hindsight is 20/20". Sometimes this results in hard feelings... even from people who were good friends. It's an outcome that happens surprisingly (and unfortunately) often.