"Hello Rob! It's been a long time since I last saw you! I once thought you were useful. I heard you were retiring, so you no longer need that junk! Haha, bye Cormack!"
"I once thought you were useful" - no it actually means "I thought I'll avail myself"
btw. "altes Haus" is something like "old buddy"...literally it means "old house" :D