What does the message "62 days ahead" message mean?
My full node has finished synchronizing (I confirmed this by comparing my block height with both moneroblocks.info and Explore.MoneroWorld.com)
The message means that your block height is 62 days ahead of a block which you just were told was mined (on top of a block way back in history).
As you verified your block height was correct (as of the time of that image)
The blocks that you are "62 days ahead" of were created by miners that remained on Monero chain(s) that we hard-forked away from.
Monero's PoW algorithm (CryptoNight), by closing the performance gap between CPUs, GPUs, and ASICs, has become one of the more profitable coins to mine with a botnet. There are a number of infected computers believed to still be mining on the old chain(s) without knowing it.
Botnet operators may or may not choose to attempt to upgrade Monero botnet miners (assuming they retain sufficient control to do so which is not always the case) depending on profitability calculations vs increased risk of detection (when making the upgrade) and other factors.
Not every miner on the wrong chain is part of a botnet. Some miners choose not to move to a new fork (see ETC vs ETH mining today) on purpose and others do not follow Monero closely enough to upgrade in time.