Depends.
Let's say your son was born in 2010 in England or Wales for a minute and you named him Harry.
Your Harry would have been one of 6,862 boys called Harry.
There might be other boys called Harry although with different given names:
Henry - 2,239
Harrison - 1,943
Harris - 129
Harri - 116
Harry-James - 14
Harrie - 10
Harry-Lee - 5
Harryson - 5
Harrisson - 4
Potentially, your Harry would have been one of a very large number of babies born that year with the same name.
You can see why all of those mums and dads went with Harry - it's a great name! - but the fact there are so many of them would put me right off. Would I want my son to be one of a few in his class with a couple of Henrys and Harrisons too?
Had your Daniel been born in 2010, he would have been one of 4,330. Obviously Daniel would have been a very popular choice too (No. 11) - but over 2,000 more babies were called Harry (No. 3).
Personally, I'd rather go with something a bit less popular. That doesn't mean you have to pick something weird or unheard of - for example, Peter (400 boys), Anthony (398), Hugo (394), Adrian (266), Scott (225), Barnaby (214), Laurence (122), Douglas (98)... Yes, Hugo might be one of a few others in his class but, going by numbers alone, it's a lot less likely.