Agreed^.
A dog is a pretty big stretch in school. I got my first adult rescue years back and I was in school. That was pretty brutal at times. I can't even imagine the kind of stress a puppy during school would produce.
Some folks just need to experience something themselves and don't put a lot of stock in anecdotal advice or others' experiences. That's totally ok, I am 100% that way too. But let me tell you, as someone who does indeed think like that, I wish I would have listened to others more, at least on this matter. (FWIW, I hardly EVER say, "gee, I really should have listened to XYZ after all," so that ought to tell you something!)
Yup. Especially considering that's such a tumultuous time to begin with. Having a puppy while being a full-time student is majorly stressful enough, so just wait until life throws you the inevitable curveball. All the stress, anxiety, and general malaise is amplified a thousand times over. Trust me. And of course, it would happen at the worst time.
This past fall, my reproductive organs had a little whoopsies. Fixing/deleting said "whoopsies" had some complications and I ended up in the hospital on and off for 3 weeks. Naturally, I couldn't really go to work AND school during all this. But I still had the dog to take care of, so I had to make a choice and ended up withdrawing from the semester so I could focus on working in between hospital and doctors visits. It was past the university's cutoff date, so I wasn't eligible for any tuition refund. So, that was about $8,000 completely down the drain with no credits to show for it.
Obviously, I'm not saying that you're going to end up in the same situation. But life has a funny way of getting in the way and having another life that you're responsible for complicates that. Big time.