Puddle under the Porsche?

So ok, I live in the great american sourthwest and it runs from warm to hot this time of year. So when I want to get something done I do it early. Just after sunrise and my cup of tea I wander out to the garage 'cause today is the day to clean the damn garage and I don't mean the messy kind of way garages get by just throwing stuff here and there over the year, I mean there are still piles of leaves all down both sides and a foot deep in the corners. First things first, I have to find the lady Diane's car keys so I can mover her car out of the way. I know what this means, her car keys are in her purse, aka, the black hole. On the plus side, she is pretty good about keeping her purses in one general location, somewhere in the kitchen or dining room. I head back into the house, put on water for a second cup, and scan the horizon for "the purse." Ok now I know she keeps the keys in one of these side pockets where she also keeps other essentials like lip balm, snow scrapers, the odd lug wrench and misc stuff, on second dive I locate the keys. Water is boiling, make some tea adding sugar and lemon and back out I go. Temp is now 76 (90 in the garage) so I get in her car, but wait, my truck is in the driveway, get out of her car and move the truck, wait, this is friday and that means trash pick-up day, park the truck on the street and start rounding up the trash to go out (shoulda done this last night) was sure to get the little bucket under the sink and always the one in the office. Go then get all last weeks newspapers that are in the laundry room. Now to get the trash barrel to the street but should I clean the garage first becuase I will just have more trash after but it'a already 8:30 a.m. and the trash truck will be here any monent (ok usually between 8:30 a.m. and 2 p.m.) Well the hell with it, I just put the trash barrel at the curb and move the lady's car onto the driveway. Walking back into the garge towards the Porsche I see a large puddle on the floor. Now anyone that has a clue knows Porsches don't have water to leak cause they don't have any water. I am confused. Get in the Porsche and start it up waiting for the oil pressure to hit normal and ease it outside beside the lady Di's car and back to the water.
It's a puddle alright and the water's coming from the water-heater in the corner of the garage. That damn plastic drain valve I been expecting to leak for the last year as finally done it and now I can go get a brass valve and be done with this plastic valve nonsense. Oh yeah, but first I should sweep out the garage while it's not too hot so I get the push broom we bought last fall and put it together, pull the big piles of leaves from the sidewalls and the corners and notice i have not only a puddle of water but now developing a mud wrestling arena in the middle of the garage as the water is still running from the valve on the water heater. Can I tighten it up just a bit and slow down the flow? I try. I grab a couple of plumbers plyers and have a go at it. Water is no longer dripping, it is flowing. Ok take a gander at warped and mutilated plastic valve to check the size valve I need and damn! it's got a 3/4" brass intake on one end, a 3/4" plastic outlet in the middle and a 1/2" plastic valve. Ok I think, I guess that's the way they make them these days so off I go to the big box " everything you need" store and find the plumbing department. This should be easy I'm thinking, and after reading a few signs I find the plumbing dept. So I'm thinking fittings and valves and such should be easy to locate. I'm wrong. So I ask the fine young man in the orange apron where I would find valves for water heaters. He looks at me. I look back at him. Silence. "well, they maybe over in aisle 17, I'm not sure what's over in aisle 17" I tell him I can find aisle 17, thank you. I
17 find aisle without assistance and almost immediately find "water heater valves" I find 3/4' in=3/4" out and next to those I find 1/2" in=1/2" out. I don't find 3/4" in 1/2" out. I also don't find anyone to even ask a question. I'm thinking pretty hard by now and beginning to sweat. Ok, I think, I got it wrong on one end or the other, I go home.
I check and recheck; 3/4" in and 1/2" out. OK I got it, I'll simple replace the plasic valve stem and core with another plastic valve stem and core and since the valve is 1/2 " it should be easy. Back to the big box with the yellow apron. I find the valve stem/core in 1/2" and I'm set. $3.89 and homewad bound. I take out the old valve stem and stick in the new one . Oops, the one valve, the old valve, is a 1/2' stem with a 3/4" core. Weird I am thinking. So back to the big box, with the yellow apron, and get a 3/4" valve, $3.99 and I'm home. I take apart the 2 valves I have bought, slide the 1/2" stem into the 3/4" core and button it up. Works just like it was meant to. It's now 3:30 p.m.: the trash is picked up, the puddle is evaporated and I still have a damn plastic valve that I will have to replace sooner or later, or, should I just get a new water heater?