I used to have a hard time understanding the intimate friendships between other women. They talked multiple times each day, texted encouragements like, “You got this!” and shared emotions more intimate than romance. I couldn’t help feeling both envious and smug. An engineer and Silicon Valley entrepreneur, I had adapted by deriding the girlish sentimentality I couldn’t seem to understand. My friend Amy, in constant contact with her best friend Alyssa, tried to explain it to…