How much should you trust your first read on a player?

I’ve noticed that sometimes I form an opinion about a player quite quickly based on a few hands. For example, if someone raises several pots early, I might assume they are aggressive, but later I find out that the sample was too small and my first impression was completely wrong.

I’m curious how other players handle this. Do you usually make an initial read and then adjust it as you collect more information, or do you prefer not to label a player until you have a decent number of hands?

I think one of the hardest parts is knowing when to trust your observations and when to recognize that you simply don't have enough information yet. How do you approach this?