It doesn't make sense, his uncle saying that to him. We know it makes sense, but his uncle doesn't know he's a superhero. Would Perry White ever say that to a young Clark Kent?
It makes sense with the rest of the conversation (in the original book and various ret-cons and reboots). The power Uncle Ben thought he was talking about were the normal powers of a person, the power of thought and knowledge (remember Peter was already a nerd with a potentially bright future), the power of love and caring, the power to influence and assist. It was really a “you can do anything you want, don’t want to be a screw up” conversation that just had much larger overtones.
Perry White might say that to Clark Kent in the post Alan Moore era, prior to the 80s the DC universe was primarily populated with “flawless” heroes, the most notable Superman with the perfect chin, perfect hair, and perfect belief system. Stan Lee took Marvel’s heroes in a different direction pretty much from the start, Marvel’s heroes have frequently been confused and conflicted, they have real world problems like having to pay bills and not always getting along with their relatives. In the pre-foible era of DC Clark Kent would never need a pep-talk about anything, he would never get in a situation where the stresses of work, family and tights are impeding each other. Peter Parker was already in a situation where the stresses of school, family and just plain adolescence were causing him problems, then he gets super powers and his life really becomes a mess.