I was told I had it after attempting suicide...I thought either it was normal to feel like crap or that it must have been a reflection of me being a crappy person and somehow deserved that feeling but yeah didn't recognize it as anything till that. But I've had it chronically for a long time...some people have more of a noticable first memory, but they also have a memory of 'before the depression' I personally don't remember a time I was without it.