I'm only 2 ½ years ahead of you but here's what I've learned so far.
1a. Don't assume that all-grain is automatically better than extract. Water chemistry, hops, yeast, fermentation time & temp, adjuncts, fruit ... all contribute to the recipe.
1b. Also don't assume that jumping to all grain has to be hard or expensive. You can switch to all grain BIAB with your existing hardware + a grain bag.
1c. Don't assume that switching to all grain is a one-way street. The shorter brew day of extract fits my life better right now; so that's what I'm doing right now.
2. Don't assume that bigger is automatically better. I've settled on 8-10L as the batch size that works for me.
3. Don't assume that gadgets make better beer.
4. Don't forget it's a hobby: it's supposed to be fun. Find what works for you and makes beer (or cider or mead or wine) that you like.