First I will tell you the stages of a dog and then we will discuss all of it with goods and bads so you can decide if you will adopt a puppy, an adult or a senior dog.
Stage 1: Neonatal - 0-2 weeks
Stage 2: Transitional - 2-4 weeks
Stage 3: Social - 3-12 weeks
Stage 4: Hierarchical - 3-6 months
Stage 5: Teenage - 6-18 months
Stage 6: Adult - 2-3 years
Stage 7: Senior - 5-10 years
The Great Dane is typically a gentle giant, easygoing and mild-mannered.
He needs only moderate exercise, but does need space and shouldn't be cramped into studio apartments and postage-stamp yards. Above all, this sociable breed needs companionship. He doesn't do well when left alone.
With his deep, resounding voice, a Great Dane won't fail to announce visitors, but guarding and territorial instincts vary. Some lines and individuals are friendly with everyone, some are sensibly protective, while others are standoffish or skittish.