When I first learned to sail, I realized that using the terms port and starboard was the answer to life. I was much better at reacting to starboard than "my other left". There is some scientific reasoning for this. There are those of us who have ADHD tendencies, the reason of which is that every word is represented by a picture. We don't see words on a page, we see the pictures in our minds that represent each word. In life, left and right changes as you face different directions. This means the word picture is confused and often is wrong, as it looses its meaning every time you turn. Port and Starboard does not change relative to the boat, regardless of which way the boat faces. Port and Starboard are less about a direction that is ambiguous, and more about sides of the boat. For the word picture, one divides the boat in have. Everything on the left half is port, and everything on the right side is starboard. For left and right, we don't normally look at our body and reference a direction, so the word picture is not as concrete and is easily confused, as what we see constantly changes.
As to you boat trim not being what you expect, something I noticed recently is looking at my telltales that are stuck on my jib. Previously I had been playing with sail trim primarily as letting the sail out and finding where it flutters, and then pulling it in some. I've noticed with the jib that results in the leeward side of the sail stalling in the lower section of the sail. Pulling it in till the telltail comes to life, and I noticed the boat pick up speed. In your case, a factor you may not be considering is that as your boat speeds up, your apparent wind chains, which is what the sail sees. The faster the boat goes, the tighter the trim will need to be. I find sailing in moderate winds, that I go from my boom most the way out to about 35 degrees or even less.
I would also suggest that if your sails are blown out, the extra bag will stall the wind much easier. Putting the boom to center may have taken some of the bag out of your sail, and you may have had a larger area of the sail working for you. Most of your lift comes from the luff. If the luff end is baggy, your trim may not be what you really think it is.
As to you boat trim not being what you expect, something I noticed recently is looking at my telltales that are stuck on my jib. Previously I had been playing with sail trim primarily as letting the sail out and finding where it flutters, and then pulling it in some. I've noticed with the jib that results in the leeward side of the sail stalling in the lower section of the sail. Pulling it in till the telltail comes to life, and I noticed the boat pick up speed. In your case, a factor you may not be considering is that as your boat speeds up, your apparent wind chains, which is what the sail sees. The faster the boat goes, the tighter the trim will need to be. I find sailing in moderate winds, that I go from my boom most the way out to about 35 degrees or even less.
I would also suggest that if your sails are blown out, the extra bag will stall the wind much easier. Putting the boom to center may have taken some of the bag out of your sail, and you may have had a larger area of the sail working for you. Most of your lift comes from the luff. If the luff end is baggy, your trim may not be what you really think it is.