I marked my centerboard line so I know clearly when the board is all the way down.
If yours is difficult to raise, I have two theories for most common… the first and most likely is that if the line has swelled with age the added friction could be a problem.
The other is I now know at at least 3 boats, mine included, that have had damaged centerboard bracket assemblies from age and corrosion over the last couple years. In the case of my boat, the pivot holes had more than doubled in size so the pin was jamming up every time. It was like lifting an elephant. Now that I replaced my line and bracket, I can pull the board up by hand (although the winches definitely still help).