Shit on balls. SHIT ON BALLS. I hate this!
Don't worry, we all do :0 it's not a fun thing to go through. Pain in the ass all around, generally. Epilepsy sucks, but it doesn't have to. It doesn't have to ruin your life, and frankly if you can charge past the initial side effects you're feeling now, and attain seizure control, Keppra is one of the top-tier meds in terms of livable side effects. Hell, look on the bright side: It might even block your absence seizures! As for kids, it's hard to say; I'd recommend doing some research, I know very little about that.
For a few of your other questions though: Will it always be embarrassing? Probably. I doubt you'll ever experience someone telling you something that horrifying ever again though. I tell people I have seizures only because it's lead to me being unable to drink, unable to do all-nighters, unable to drive, and my medication has some wonky side effects that I can't wiggle out of in social situations (read: when upping lamictal dosage, I experience minor hallucinations which are hard to discern from reality). I'm probably in the median range in terms of how annoying epilepsy can be; Keppra's side effects are too extreme for me as are many alternatives, but at least I get OKAY seizure control, enough to not have seizures in front of my buddies. Hopefully with higher dosing, I will be able to make it to the six month mark and be able to drive again; possibly even be able to drink.
Is it possible to just develop it at 31/is it possible this is a one time thing? Yes, unfortunately. It's called adult onset epilepsy and it's not even that rare. Your odds of developing it were increased significantly by having these absence seizures throughout your earlier life, though. Your doctor has put you on Keppra and I think he's made the right decision, regarding your history at least; if you go off it, you may have more seizures, which in turn lower your threshold for future seizures, which in turn...you get the idea. It's best to have no seizures if you want to continue having no seizures.
Will you always feel so negative? Nevar! Your almost-sarcastic angry approach to this situation is exactly where you should be. You're totally right in that this is a bullshit situation affecting your life in a way that I'm sure you never wanted to happen. I feel defective sometimes, but then I remember that I'm not always totally useless, and in my not-useless moments, I'm oddly creative. Seizures do something odd and not completely understood in the brain; it's almost like a dream state, but more extreme; your brain is processing not just the day's events, but pretty much anything you had in your available conscious memory. Those ideas and concepts will feel jumbled up and vague; familiar, but out of reach. Memory loss happens, but it happens in the oddest manner which, if you learn to live with it, is simply a different style of being; the memories are there, just...stored differently. As someone who grew up with it, I can only say: Push hard. If you have a seizure, don't give up; struggle back onto your feet and you'll feel better for it. It might affect who you are - in fact, it definitely will - but if you trust your family to be supportive, you'll be OK.