You've had one big screw-up - [Soft of.] - learn how to avoid it happening again.

[Truth be told, that's the easy lesson. He doesn't want to say to Luke, "learn how to deal with being betrayed" or "learn to not be so trusting," but...]

Learn to judge people's intentions more accurately. Learn to make decisions for yourself instead of relying on others to point you in the right direction. You're starting, but you're not done yet.