I too have a trusty old 06 that was given to me when I was around 5 years old by a uncle. I used that rifle for everything from ground squirrels to elk and everything between. I would hate to actually think of the number of rounds that rifle has put down range either on targets or animals, but.........how boring life would be if we just struck to one caliber when there are so many out there. Some are better at things and some are worse but they all have a place in my heart.
I have retired that old 06, the barrel is shot out and I have no idea where the second shot is going to land. I thought about re-barreling it but decided to leave it as it is for the memories.
For other calibers I have a lot of them. Starting with the .22 center fires going up to a .338. They all have a place in my safe and they all have taken game animals. It is hard to say just which one is my favorite, perhaps it is the .340 Weatherby that went to British Colombia and Africa with me, it also took my largest elk and deer to date. But then there is the .26-06 that is quickly gaining a place in my heart and will be with me on my coues deer hunt this year in Arizona. There is also the 7mm Rem mag that I purchased to give the old 06 a rest. It has taken more game animals than most hunters will ever shoot at. Or even perhaps my dads old .300 Savage M99 that I used a couple of years ago to take a deer and then put it away after cleaning it.
There are way too many calibers and rounds but then that is what makes life fun. If you only have one and shoot it well then I'll tip my hat to you. But if you are also like me and have a safe full of them I'll do the same.
There is a old saying that goes something like this; be ware of a man that only has one rifle, for he knows how to use it.
I like to modernize it a little by saying; be ware of a man that has multiple rifles, for odds are he knows how to use all of them well.