This is one reason why I'm against even seemingly mild self-disclosure in therapy...

Having said that - it seems likely to me that you're making a lot of assumptions about your T's current life and past experiences. I know I do it with mine - his life is perfect!

Also, I think human experiences are often more universal than you think - for example, everyone has felt lonely at some point. Everyone knows loneliness. No, they may not have felt it deeply and chronically and over a long period - but they understand what it is.