I started as a kid mainly going through my parent's change back in the early 80's and for many years I occasionally got my mom to go to the bank for me to get $10 in pennies (and exchange out the old ones). I pretty much skipped my college years except for occasionally searching nickels when I was at the casino. Pulled my first buffalo (4 holes drilled in it) and my first war nickels doing that (mid 90's).
From when I finished college until about 2004, I would occasionally go and buy coins at the bank, but at the time I had a bank which was stubborn about selling even 1-2 rolls without charging a fee!!! Since I refused to pay the fee, I usually didn't get coins in any large numbers.
About 4 years I moved and was then close enough to one of the Indian casinos in my area that still had coin operated slots, so in 2005 I remembered finding a few war nickels in the slots and thought they had a better chance than at the bank, so I started going late at night on weekends (midnight-5AM) after primarily nickels with occasionally quarters mixed in. Found my oldest nickel to date in that first 6 months of casino hunting (an 1883 V-nickel "No Cents" variety). After awhile, I started to buy boxes of pennies at the bank (I had switched banks to one with no fee) and eventually tried nickels. And in my first box of nickels, got 4 buffalos and like 3 war nickels. At this point, I realized that going to the casino was no better or worse than going to the bank, so I started doing boxes at the bank when I could afford them instead of only the casino. And then eventually found a few local bank(s) that would sell me bags from their coin machines and well, the rest is history. So now I primarily just buy bags off coin machines and rarely get boxes. If I had more time I would probably supplement my low weeks with boxes, but I am so busy that I barely find the time to keep up with the bags I buy once a week.
Most of my collection is from roll hunting or other various methods of hunting for coins at face value. I inherited a very small amount from my dad and I have bought a few coins as well as one small collection, but otherwise the rest is from finds. I just find it so much more fulfilling to find it at face value than buying it. I guess its the thrill of the hunt that I find the most fun. You also just never know what you are going to find.
My oldest coin found in circulation was an old Roman coin, Constantine the Great (320 AD minted in Siscia) that was found earlier this year.