Just realized this is an old thread, but sod it going to reply anyway as it seems to have resurrected.
I am utterly In Love with my dog and have never regretted having him - had him from 8 weeks, he's now 9 years old. When I met DP he had 2 dogs of his own, (one of which sadly died in my arms with me cradling him), so I had to get used to being a one-dog woman, to living with 3. It was lovely!
I can honestly say that my dog has never been a problem, he's so gentle and easy going, a dream to train, and just fits in to my life. He's a German Shepherd, and I do think people should do lots of research on what breed type they want before they get a dog. Different breeds have different needs, different energy levels and different health issues.
A lot of the comments on here show that people perhaps aren't prepared for the lifestyle change, or maybe don't really want the lifestyle that a dog brings but are persuaded into it perhaps by a partner or children.
Yes, the house is messier, smellier, and I've given up on ever wearing smart black clothes because of the hair. Yes it's a bind, in that you can't leave them all day - but I do equate it to having kids. You don't resent the difficulties children bring because you love them. Same for the dogs.
I really do think that if you don't think you'd like the hassle, the bind, the mess then you're not a dog person and it's probably best for you (and certainly any potential dog you might have) not to get one in the first place.
(I'm not being judgey here by the way, it's perfectly legitimate not to want those things and I respect people who say they don't want a dog because of those reasons)
OP said something upthread about why so many rescues have 18 month old dogs. It's because people fall for the puppy stage, then they stop being cute and reach the bolshy adolescent stage. The novelty wears off and they get rid.