“Because I like it” is a complete reason. You don’t owe a presentation on why you love birdwatching.

Liking something is already a reason, but the habit of justifying makes it feel like a rough draft that needs defending. That habit usually comes from somewhere: a room where your interests were treated as odd, or a feed where everything has to be explained to strangers. Enjoyment does not become more legitimate once you have argued for it well.

Next time someone asks why you are into something, try the plain answer and stop there. Notice the urge to add a paragraph, and let the silence sit. Keeping one interest entirely unexplained is good practice for keeping the rest of yourself unexplained too.