I just started learning the piano again, and using modern apps (such as Simply Piano) makes it actually fun. Ten years ago, I couldn't bear through reading sheet music, making mistakes and got discouraged. But now, learning to play is like playing Guitar Hero. You get instant feedback, guidance on what and how to play. It's great. We'll see how long it stays "fun", but atm I'm making progress every day.
As your music ambition grows, at some point you'll get to the hard part: building the 5-way translation between what you hear, what you play, what you sing, what notes you see on the page, and what sounds you imagine in your mind. The more time you spend on only one line in this pentagram (for example translating from notes on the page to playing an instrument), the bigger the "imbalance" will be when you eventually realize you need the entire pentagram. You'll turn to sight-singing, dictation, audiation and all these other exercises everybody hates, your progress will be slow and difficult, but by then you'll know why it's necessary.