I've had him almost 2 months now, and he's never had any problem with me coming up to his tank until the past 5-6 days. Usually, if I put my finger to the tank wall, he'd swim over and follow it around. Suddenly, he stopped doing that, and instead... he's quickly backing away if I put my finger to the tank that way. If I keep my finger there for awhile, he will sometimes flare at it.
He doesn't seem sick, just scared. Otherwise, he's eating and swimming around like normal. I haven't changed anything in or around his tank, nor his food or the frequency I do water changes.
Maybe I just scared him somehow? I can't recall doing anything to spook him this way. But if that's the case, will he get over it? Anything I can do to help him get over it?