I understand where you’re coming from, but I think the way to deal with them is to look at them from different angles 🙂 I can’t think of examples for all but hopefully these will help a bit:

When people say you don’t need another person to make you happy, in my experience they’re nearly always referring to romantic partners, but romance is hardly the only type of meaningful social connection you can have with another person. A lot of people will try and deny that, though. Single/no real friends doesn’t necessarily mean ‘isolated’.

Failure: everyone experiences it, most people hopefully learn something from it; perseverance is important as well. Broadly speaking, you can’t succeed or indeed get better without failing, really.